 to the BAA Christmas Lecture 2019, that made many thanks for coming along and making this one of our most successful events that certainly capacity again. As new president, I'd like to welcome you all. I would actually notice that you may on the, looking on the website that it did actually come, the part from the president's introduction bit that came up as Alan Dowdle as president. So I'm quite sure that Alan wanted to take over now, but I think the shortest running presidents has been a year, so I didn't want to ask this a few weeks, but. Anyway, can I initially express thanks to two people? It's the longest it's thanks at the end, but I just wanted to express thanks to the IOP for letting us host the event here, and also for somebody who, if in their absence, the event wouldn't take place, is Hazel Collette, the meeting secretary. So I'd like to just if I can ask for a round of applause for Hazel because she's put in so much work as always on this, and I appreciate that. So before we move on to the actual, the talks that I've, one of the enjoyable parts of the president is to actually to be able to present awards for people who have been notable in astronomy and that first one is Robin Ledbetter, who was awarded the Merlin Medal. So if you'd like to... Did you want to come up once? Thank you, thank you, thank you. Oh, I think I want to do that. And the Merlin Medal itself. Thanks so much, Lee. Did you want to say a couple of words? I've spent a lot of people knowing me. I'm the spectroscopist. How many star analyzer owners are there here? Oh, look at that. Fantastic, I hope you enjoyed it. You know, Elliot Merlin himself was a spectroscopist. He took spectra or used a spectroscope to view Novi over 100 years ago now. But it was another metal holder, Maurice Gavin, who got me into this game. And of course, he was a pioneer of spectroscopy in the digital era, the electronic era with electronic cameras. And thanks to that technology, amazingly enough, we can still take spectra of those Novi that Elliot Merlin viewed over 100 years ago, despite the fact that they're now over 100,000 times fainter. And I'm very honored and privileged to be part of that history. And thank you very much for awarding me the Merlin Medal. Thank you. Thank you. The next award is the Patrick Moore Award, Sir Patrick Moore Award. Due to a generous donation to the BAA after Sir Patrick's death, the fund was created, or the award was created, for someone not necessarily within the BAA, but somebody in astronomy carrying on the ethos of astronomy and outreach to the general public, and for doing work to promote astronomy, both with youngsters. And each year, there is a small committee within the BAA who receive the nominations, and that goes to council with their proposal or their suggestion, and then that's approved. I'm delighted to confirm that Dr. Stephen Barrett was the winner this year, and has come along to collect the... With great pleasure. Thank you. It's nothing I can do. Thank you. Thanks a long time. That's all right. Want a handshake again? Thanks very much. Thank you. OK, so from the next... This is more of an admin session. If I can just ask Jeremy to announce the papers that were confirmed at the council meeting this morning. Yep, so this morning council approved the publication of two papers in the journal. So the first one is determining the distances and distribution of young star clusters using Gaia Data Release 2 data. That's by William Sampson. And the second paper is Sonspot Numbers Without Active Region Numbers, and that's by Peter Meadows. Thank you. Thanks a much for your time. OK, so next our speakers this afternoon. Now, Dr. Mark Kedger has very kindly come over from Spain this afternoon, not just for this afternoon. I just explained a little bit of background about my local astronomy society. He's down in Basin Stoke, and I've known Mark for a number of years now. It's notably he's been coming over to give talks to the astronomer magazine run by Guy Hearst, and he's attended several of their AGMs down in Basin Stoke. And over the last four years that we've been arranging for Mark to come over to talk to our society. And we've flown him over and we've tried to sort of split up or split the cost with other societies if it worked out. For this year, with becoming president, I sort of approached Mark back in June time, no, April time, I think it was, to ask, would he be prepared to come over, but not just to talk to Basin Stoke but to do the main BAA lecture today. Oh, and by the way, if you're coming over, would you mind talking to Basin Stoke as well? Would you mind if we arranged for Newbury to come in as well? So what we came up with the idea is that the BAA would pay for his flight over, but as part of our outreach to the wider astronomical community so that we could, more people could enjoy some of Mark's excellent talks that we've done, did three talks and just to put the icing on the cake, as far as Mark was concerned, I said, oh, can the talks be different? Are they coming to different ones? And so, oh, yes, I'll agree to that as well. And then Northampton muscled in on as well and said, oh, here you're coming over, so please can we have a talk? So Mark is doing three talks and probably, he's not quite sure what talk he's doing on the Monday to Northampton, but a busy weekend for him. So Mark has previously worked over in both Tenerife and La Palma on the observatories there and working on the I think Newton in La Palma and Herschel. Since 2006 he's been working for ESA noticeably on the Herschel project and in 2016 moved over sorry, 2018 moved over to Plato which is the search for Earth 2 Earth-style planets which is the subject of his talk this afternoon. He writes monthly on comments and meteors for the Spanish Astronomy magazine. He also contributes notes for the Astronomers magazine on the comments and does a bit of enjoying his cricket or watching cricket and I think it's just something that you can look up on the spin the science behind the spin of a cricket ball. Something like that. So I remember that so that came up as a cricket one. So without further ado if I can pass you over to Dr Mark Hager and give it a warm welcome. Thank you, Alan. Does this work? Good heavens, it works. Right. What Alan didn't point out is that he also arranges for interesting journeys. And this year he has excelled himself. Quite apart from the fact that I got the extra talk at it on I heard a couple of months ago that I needed to be at Estec in the Netherlands for an important Plato meeting on Wednesday. No problem. Last flight from Madrid to Amsterdam Tuesday. Last flight on Wednesday. Catch the plane to Basingstoke Basingstoke Airport or whatever the appointment is. On Thursday, he had it all sorted out. And then I got, as I was leaving for the airport Tuesday evening, I got a message from BA your flight has been cancelled and you have been rebooked Wednesday evening. If there are any French air traffic controllers in the audience, would you please leave now? It turned out that there was one spare seat on one flight on Thursday and they managed to get me on to it. That wasn't Alan. That was a very helpful guy from Iberia. And so I actually did manage to arrive only to discover that Alan had arranged a train strike as well. You are in for an interesting year. Anyway, subject today, I'm going to talk about Plato and I'm going to talk about the search for Earth 2. However, as we are not NASA, we are not going to hype this up. One of the things I would tell you is, please be very cautious of the weekly press release that says we have discovered a duplicate of planet Earth. It is not true. Very few of them, if any, look even remotely like Earth. So, where do we start? Well, let's start with this quote from our Director-General because he's got spies everywhere so it's a good way to start. Does a second Earth exist in the universe? One of the most exciting questions in astrophysics today. And that's one of the reasons why searching for planets around other stars and searching for possibly habitable planets is one of the biggest priorities of the European Space Agency. And we've actually got three planet search missions launching Cheops, which the latest I heard is it was going to launch on December 17th. Plato, which will launch in 2026. And then Aerial in 2028. Oh, I'm not, sorry. I did not. Yes, sorry. I thought that had been set up. I wasn't looking behind me. Yeah. You're an audiovisual expert. You know your computer. Oh, right. Ah, wrong button. That's a good start. That is a good start. Right, now we pay homage to the Director-General properly and we can continue. So, there were many years of announcements. We've found a planet famously Barnard various other stars, Epsilon Eridani and others. None of which were actually confirmed. And after finally 30 years of searching, Michael Mayer did air-killers, finally found a planet and it's around 51 Pegasi. Maybe if you're 5.5 star it's there. It's not actually difficult to find with a naked eye. But image, you know, you can't see the planet. It looks just like any other star. But the planet was a bit singular. It was the first of what we call the hot Jupiters. So, this was a very unexpected development. A star that's around about the size of the sun, the planet has an orbital period of 4.2 days and a surface temperature of 1200 degrees centigrade. Not even NASA would claim that is Earth-like. At least on a good day. It was a very disconcerting discovery and it was a big challenge for the models of star formation. And it turns out, out of the first 300 exoplanets, planets around other stars that we discovered, about 80% were like this one, hot Jupiters. Jupiter-sized planets very close into their stars. And there were also a few very large rocky planets. But nothing that looked remotely like our solar system. There was this one, 51 Cancri. This was the first one that started to look a bit like our solar system. There's a whole series of planets. Multiple planets. One of which is around about the orbit of Venus, but with a quite eccentric orbit. Five planets in total. They vary from about 8 Earth masses to 4 Jupiter masses. They're not exactly holiday spots unless you mean like being crushed. Quite painfully I would suspect. And it got to the stage where people were starting to wonder if our Earth was actually exceptional for some reason. This is one of the most extreme ones. 1 to 1B. Great holiday spot if you like sunbathing at 2500 degrees centigrade in an atmosphere of boiling crust. The atmosphere contains lots of oxides of very refractory metals because the planet is literally boiling away. I checked up the numbers before I left and NASA lists 4,099 confirmed exoplanets as of when was it? Sunday or Monday I think it was the second. And there are nearly 6,000 unconfirmed planets. Of those less than a thousand confirmed mass. So unless you know the mass of a planet as well as its orbit you really don't know if it's even remotely like Earth. And if you go through the list you'll discover that only 15 of these more than 4,000 planets are Earth size or smaller. 107 of the planets with confirmed mass are at least 10 times that's where calling it as a planet is a bit of a stretch. You can call it a planet if you want but it's more like a failed star and the list is really dominated by those optupiters. Why have we found so many? Well it turns out there are around about 50 planet search programs in the world. Almost every observatory seems to have its planet search program. I think even Roger Dimmert's got a planet search program these days. But they are mainly dependent on very high resolution spectroscopy. Now there's a challenge for the gentleman in the audience our spectroscopist. Very high resolution on very large telescopes. Very slow it's demanding and the easy way to do it is to look for stars with short period big planets where the shift in the spectral lines, the Doppler shift from the gravitational perturbations of the planet of big. It's very difficult to have a lot of patience and look at a star over many years to detect a planet like Jupiter in our own solar system. To detect that you would have to observe one for at least a dozen years and probably longer to be able to confirm it. There's a natural bias to looking for big planets close to their star short periods more distant planets it's very difficult to find them normally in the small planets you can't even detect. But there is a alternative method for doing it. This is the one that people are beginning to use with a lot of success now but you've got to be very patient. Fortunately astronomers can be very patient sometimes. That is to look a big patch of sky and wait until a planet just happens to pass in front of the star so like the transit of Mercury a few days ago which I spectacularly failed to observe third consecutive transit has been clouded out for me don't observe transits of Mercury with me, you'll never have any luck. Only about 2% of stars will actually show transits but this is a very good way of looking for smaller planets. However there's a problem there are so many processes that can mimic a planetary transit star spots stellar activity stellar oscillations the rotation of the star there are various other effects and only about 50% of all the transit candidates that have been detected over the years have ever been confirmed because you confirm them with spectroscopy so a lot of the Kepler planets have never been confirmed because they are too the stars are too small too distant, too faint to be observed with the technique from Earth now this is your ideal transit there's your little planet this would be about something like Earth or Venus transiting in front of the Sun you get a nice little dip in the light there that's the theory practice though of course never quite so simple this is a normal transit like Earth this is a very big transit this is planet comparable in size with Neptune now you've got to imagine that you're like Jocelyn Bell Bernel who had three or four miles of paper trace and she was looking for little pulses in that because that like Earth instead of being a little section that fits on the screen it would go all the way up to Northampton and probably most of the way to Bristol the other side and you'd be looking for that little noisy dip in the middle which is actually the planet that's the trick in looking for transits it looks easy there's not a lot easy about it however NASA's Kepler satellite refined the techniques for doing this very nicely it's a 1.4 metre telescope it was put in an Earth trailing orbit so it just very slowly moves away from Earth it's about 0.1 AU per year it's moving away and it has a camera that is 95 megapixels that's a decent size camera bit better than my mobile phone anyway and it takes constant exposures of a field of view in Northern Cygnus here's its field of view not quite overlapping fields you see Denneb Alvario there and it just looks at every star in that field of view looking to see when one of them winks slightly that's where the patients comes in so here's the field of view a little bit larger it's 12 degrees across and it's observing 150,000 stars simultaneously which is pretty good there's plenty of data there it takes photometry to a precision of 0.02 not magnitude million magnitudes that's 20 millionths of the magnitude which is pretty good so it's just looking for stars with periodic dips in brightness and there are a lot of other missions that are going to follow on from Kepler Tess is the classic this is Tess launching it's a mission that's looking mainly at red dwarf stars so when they tell you that they've found a duplicate of Earth just remember that most red dwarf stars are flare stars so any planets around them are going to be bathed frequently with hard x-ray radiation if you like hard x-ray radiation it's a perfect holiday spot I'm not so keen on it myself but no so Tess launched April 18th 2018 and started looking and has already found a few dozen planets this is one of its commissioning images now I'm sure you'll recognize this constellation if I say that's the coalsack up there this is the coalsack that's actually the constellation of crux gives you an idea of the sort of data reduction problem because there's an awful lot of stars in that field of view they're looking only for small rocky planets close in to red dwarf stars and it turns out that now after Kepler each mission has a very specialist target so Cheops, which is just about to launch is going to look at the planets that have already been discovered and try and measure their diameters much more accurately because if you measure the mass and you measure the diameter you can measure the density you know what the composition is Plato which is my mission or mission where I play a very small part like this that will look for planets around sunlight stars that's it's priority will also look at atmospheres around exoplanets earlier I met a gentleman upstairs at the registration desk said my friends bid for the design of Plato I think they supplied us with a Toblerone and Astrium supplied us with a cash register and apparently Issa decided that the cash register design was the better one so the one on the left that's the one we're using this is one of the Plato telescopes which are being built at the moment so we signed the contract for it in October 2018 Plato's had a bit of a rocky ride it has almost been cancelled twice and could still be cancelled in the middle of 2021 so if you meet me signing on at the job centre sometime in July 2021 you know what's happened not good news and also our design has kept changing a little bit we've started with 32 cameras then we had 28 now we've got 26 to cut down on weight then we started with this design last year and then the clever people who were building this thing discovered that we didn't have enough power so we had to fit it with wings so we've got extra solar panels that have been fitted to it this should be more or less the final design but it does actually mean that the Plato mission logo has now changed three times well changed twice different logos now here's Plato at a glance we're going to launch on an Ariane 6.2 now if you get this question in trivial pursuit what is the difference between a 6.2 an Ariane 6.2 and an Ariane 6.4 and the answer is it's the cluster of booster rockets at the bottom the 6.4 the more powerful one had 4 and the 6.2 has only 2 now it's brilliant the engineers have been really imaginative there now we have a launch date Emma's laughing because I think she's read this December the 12th 2026 but we have several days slip possible slip scheduled into the schedule we could launch as late as December 16th do not believe this no space mission that has ever been built has ever launched on time or ever launched remotely on time our betting is that even though we're right on schedule at the moment something will happen we have no idea what will slip into 2027 quite possibly 2028 however we will try and make that December 12th launch date put it in your diaries so I said 26 cameras and the accuracy that we're demanding of our cameras which are all individual telescopes is from magnitude 11 star integrating an hour we want 50 micro magnitudes so that's 4 zeros and then a 5 not bad right so what are we going to be doing with these cameras well we're going to be applying the Goldilocks test you all know Goldilocks she's an expert in porridge the Goldilocks zone is the zone around a star where it's not too hot nor too cold for liquid water to exist just like the porridge that Goldilocks was testing now Tess because they're looking at red dwarfs and they've got very small habitable zones around them they reckon they might find if they're lucky two or three planets in their habitable zone Plato by looking at much larger stars with a much bigger habitable zone we are hoping to have 100 plus maybe many hundreds of planets that pass the Goldilocks test however there is a warning not all porridge is actually as good as Goldilocks said so we'll leave that for a bit later so Tess and Plato look as if they're actually doing very similar things but they're actually doing it a bit subtly different they're doing it in a completely different way Tess is observing 85% of the sky two year primary mission they've already got an extension and they were hoping to find about 2,000 planets short period planets Plato will look for at least four years theoretically we can look rate and a half if everything works nothing breaks so we hope to find a minimum of 4,000 planets in four years so about a thousand a year so far Tess is doing pretty well it's got 34 confirmed planets and it's got well over 2,000 candidates are unconfirmed so if we can match that we're doing pretty well and this is just a comparison no on the left on the right hand side in the blue corner the NASA champion and on the right hand side the ESA champion Tess's field of view is 2,300 square degrees which is impressive Plato's is only 1,000 square degrees we've got two fields one in the northern hemisphere one in the southern hemisphere at one of those fields for two years switch to the other field and stare at that for another two years and we're looking at about 265,000 stars in that time so this is the design now the 26 cameras are split up there are 24 normal cameras for faint stars for us faint stars is anything we do date and we've got a couple of special cameras so we have a field of view that is 47 degrees across that's the field of view of our telescope it's quite impressive I was thinking 40, nobody's impressed I thought telescope with a 47 degree field is pretty impressive and then within it will be observed by a different number of cameras the cameras are slightly offset from each other so that we cover the widest possible field the central 22 degrees or 24 cameras will be observed and then different areas around it will be covered by 18, 12 and in the outer part 6 cameras every 3 months will rotate the field of view because the earth is going around the sun so we have to rotate the cameras so that the solar panels keep pointing correctly at the sun and that gives us a nice calibration of the cameras it makes sure that what we're seeing is genuinely from the sky not some intrinsic problem in the camera some trending we've also got two special fast cameras which will observe bright stars every two and a half seconds those are the cameras here these two four groups and then the two fast cameras the normal cameras will take an exposure every 25 seconds not bad at all however we only send back the data for our target stars I'll explain the reason for that in a moment these are our two fields of view you can see how big they are now it's going to be easier if I do it over here the northern field starts in Ophiutus Ophi, Hercules, Lyra about half of Cygnus right up to Ursa Minor it's a very, very large area of sky that we're observing so Plan A is that we will observe each of those fields for two years there's a possibility that a couple of years before launch the scientists will decide that the best thing to do is observe one field for three years then we can look at longer period planets so what's our observing strategy well, our cameras are 4,510 by 4,510 pixels and there are four ccds per camera so that gives us, if you add them all up 81 megapixels per camera multiply that by 24 cameras well actually 26 that's a heck of a lot of cameras and 25 second exposures we're taking a lot of data our diet is 436 gigabytes per day that's what we can get down to the ground station so what we have to do is go on a diet to keep ourselves down to only 436 gigabytes per day so what we do is we just download all area around each of our target stars so this is what a play to observation will look like will actually be a bit disappointing it will typically be a 6x6 pixel square the exact strategy is still being discussed it might not be squares it might be circles or polygons of some time but it will look something like this now we've got 5 prime star samples the sample number 1 is 15,000 solar analogs brighter than magnitude 11 these are our best stars these are ones most like the sun if you assume that 2% will have transits divide 15,000 by 50 that gives you about 300 stars should have planets, transiting planets then we've got 2 other samples of sun like stars, solar analogs that are either a bit brighter or a bit fainter with a smaller number of stars and then 2 other samples of much lower priority and we are going to do some red dwarfs the red dwarfs are there we can't ignore them as well just to fill in now the problem with bright stars of course they saturate your CCD this is a problem I think most of you admit sometime or other this is what the field of view will look like when we are observing a star that is around about magnitude 7 you will get an awful lot of charge leakage well actually it doesn't that's not so much of a problem we need to collect 1,000 million photons from each star that's a nice small number 1,000 million for each star to reach our target photometric accuracy so it turns out that actually these saturated stars you can recover all the flux from them it just needs a little bit of clever software to do it however the problem is that one saturated star takes up probably as many pixels as 100 or 1000 normal stars and that's our bandwidth so you don't want to have too many stars that saturate massively and one of the things that's been done with the CCDs is to design them so that they have the greatest possible capacity before they start to saturate so we will observe the fainter stars but this is what happens when you observe the faint star Plato will observe some stars right down to magnitude 15 but the light curves for these faint stars just like they were for Kepler will be pretty noisy much larger errors it's still possible to detect the planets but it's a little bit trickier basically our data reduction pipeline looks something like this so you have a mishmash of numbers coming down from the satellite to the Severeros tracking station near Madrid 35 meter antenna we have a wizard in Paris Observatory who's writing our software he waves his magic wand a bit out comes the rabbit from the hat which is our planets that's the theory my job is literally to keep the magician under control and make sure he's documenting what he's doing he's a great guy but I can't get him to document it properly he's not an air traffic controller though so that's not a problem we need a lot of clever software to do this and there are a lot of people in many different European countries some of them here in Britain at Warwick who are working on this so here's our transit again now the first problem is that when you look at a transit you only measure the relative size of your star and your planet but if you want to characterise the planet know exactly what kind of planet it is you've got to know it's diameter you've got to know it's mass that's not so easy however we have a very powerful very useful ally that's already been mentioned in this meeting that's Gaia revolutionised searching for planets because what it is doing is it's measuring the positions the distances the brightness of the stars with incredible precision it's giving us such good information on spectral types, distances, luminostas that already the planets that are being discovered by TESS are getting a mass and a diameter for the planets from their measurements a factor of 3 better than they were expecting just because the Gaia data is so good and Gaia is going to keep on observing and they're going to do even better we're coming up to data release 3 data release 4 I don't know if there's a data release 5 but still the data will only get better so this is what a typical light curve for one of our stars will look like now you may or may not have a planetary transit in that there what you do certainly seem to have is a lot of noise so you would think when you look at a light curve like that that's more than a thousand 3 years of data which is about the sort of light curve we'll get that 9.999% of that light curve is just utter junk you throw it away, you're not interested actually that's not quite true we'll be using absolutely all the data on these stars because we will be looking at these little tiny variations to measure oscillations in the stars these oscillations when the sun is oscillating these are great for telling us about the star we can get an enormous amount of information about the star its internal structure its age, its diameter its surface gravity from its oscillations particularly when we combine all this information with the information from Gaia a lot of that is genuine variations in the stars so when we combine all this data, the oscillations the Gaia data and our own light curves we reckon that we can get 10% accuracy on the mass about 1-2% accuracy on the star diameter and even we can get with Gaia 10% accuracy on the ages of the stars that's tremendous information because that tells you how how evolved a planet is likely to be if it's very young, a very old planet if its star is a very old one that's about to come off the main sequence or it's a very young star and the planets are recently formed however we can't do the observing without a lot of help now here's another very impressive number there is a huge ground-based consortium around Plato collaborating to confirm these planets you've got to confirm them spectroscopically normally on an 8 meter telescope anybody in the audience with their 8 meter telescope come up and have a chat with me afterwards we've negotiated an agreement with the European Southern Observatory that they are going to give us I believe it's 50 nights per year on 8 meter telescopes down at La Silla over the course of the mission that's a huge amount of telescope time and it is ridiculously insufficient for our needs so who are you going to call ghostbusters now some of you Roger, come on you will recognise these two evil characters won't you I mean the two on the left not the two on the right this is my friends Ramon and Montse they live in a suburb of Barcelona that's their 30 centimeter telescope we call them Big Arnie and Terminator and you can see there is actually a pretty good family resemblance there do not get Montse angry Roger whatever you put in your Facebook page don't get her angry they started looking at Exoplanets some years ago with their observatory what they do is literally they raise the telescope up on a piston poke it through a hole in the roof that's their observatory system and this is one of their lighters it's a magnitude 10 and a half star and this is the transit of an exoplanet it's a Jupiter size exoplanet but they have been confirming exoplanets for years they've done a lot of them here's another one and you can see even though the error bars on an individual observation are quite big this transit it's an amplitude 200 they've detected it very very easily indeed we are arranging a huge amateur collaboration program in coordination with the Plato satellite it's being coordinated from Austria I know the guy who's organizing it we've been talking about it he's new to amateur collaboration and I've been telling him look at these people they're already doing it so that he's got some ideas anybody in this room who's interested in collaborating with a big e-submission you've got a telescope around 20, 30 centimetres you could be of enormous interest to this collaboration one little incentive we don't go into corruption in this country is that to encourage people to collaborate there may be some free CCD cameras being handed out later but I didn't say that actually that's going to be one of the incentives that because they want very standard data they will be giving people CCD cameras standard cameras to take observations in return for these people actually using the camera occasionally to confirm our planets so if you're interested keep your eyes open however I said expect a lot of hype particularly from a certain space agency the other side of the Atlantic about planets that they will sell you as looking like this do not necessarily believe it we know that actually the Goldilocks zone is rather narrower than we thought recent research says astronauts can work in gravity up to 3G I'm not sure I'd want to do it myself but you can live in 3G and more or less remain operational if anybody wants to volunteer for the experiment I'd be delighted to hear from them temperature there is more demanding as we know our Earth there's a greenhouse effect the Earth is warming and there is a point at which the greenhouse effect will run away positive feedback goes out of control you can't stop it theoretically should have liquid water on its surface if anybody's seen any liquid water on the surface of Venus recently the reason is that if you go a little bit closer a little bit further either the greenhouse runs away or it just isn't good enough you move the Earth 3% further from the Sun and we'd probably go into something like a permanent ice age move the Earth 3% closer and you'd probably be tending towards Venus so actually when people say they're talking about they've got planets in the habitable zone a lot of them are probably more like Venus or more like Mars than they are like the Earth do not buy real estate from NASA so I said only 32 known exoplanets are less than 3 Earth masses so anything bigger than that you are not going to enjoy walking around on the surface too much of all the exoplanets we know only 16 are actually in the zone where theoretically you could have liquid water and off those there are only 3 that are smaller than 3 Earth masses and in the habitable zone 2 of them look like runaway venuses and 1 looks like an ice ball none of them in my view my humble view actually are very good candidates to be called in Earth analog so my conclusion on this is that Goldilocks's testing was remarkably deficient and we should go back and we should rewrite fairy story her porridge control zone was far too broad she was very tolerant of deviations of temperature we can't estimate how many genuinely Earth like planets there are out there it may well be that of all the Earth size planets that we discover only a tiny fraction are actually genuinely Earth like because they are really in the sweet spot to be neither too hot nor too cold but if we don't look we'll never find them and of course whether we find a planet that looks like Earth or we discover that there aren't any planets that look like Earth Earth is a free, it's a mind-blowing discovery it has huge philosophical implications everything at the moment is guesswork we really don't know what the numbers are and what the we're going to find by the end of the Plato mission we should have a good idea just how many Earth size planets there are around stars like the Sun a good idea we may though discover that planets like our Earth are extremely rare in our galaxy that would be a mind-boggling discovery as well disappointing but mind-boggling whichever way the answer goes so thank you very much for listening I've already tripped over my shoelaces twice there's no need to hide I'm sure the question is whether who's better well I should stay on my knees before you should you are the president thank you very much we've got time before tea can I ask how there was the first by about half a second I get how important it is to work out how many Earth-sized planets there are but I don't get how we can then find out the masses of those planets and surely without the mass we can't say okay so we combine the information that we get Plato only tells us the relative size between the planet and the star Gaia though tells us the distance the luminosity that tells us how big that star is so when we combine the Gaia information about the star with the Plato information about the planet put all the numbers together do a little bit of quite simple maths and out come the numbers and you can tell if it's rocky, you can tell if it's icy you can even tell quite possibly if it's got an iron core or it's a silicate planet we are going to be that sensitive just by combining two completely different missions so gentlemen there we wish you a challenge to amateur spectroscopists concerning measuring Dr. Woggle or that sort of thing the current status is that amateur are able to measure Dr. Woggle with planet down to 20 meters from the right side that's really impressive that's good enough I think that we are 8 years down the line on amateur spectroscopic capability we've gone back to doing that do you think there will be any target for the interest of the planet could well be because you've got to remember that stars from magnitude 8 to 11 are our prime targets but we've also got the fast camera that will observe stars up to about magnitude 4 there will be some planets around very bright stars for you to have a look at but we'll have candidates from about magnitude 4 down to magnitude 15 take your pick, there will be plenty for everybody well that's the problem with Kepler actually most of the stars that they've observed are so faint that even 8 meter telescopes aren't good enough for what they need do you want to use the microphone sorry not for me it's for the recording apparently Kepler and Tess they downloaded all the like curve information and that's had a great spin off in other areas I'm involved in a couple of pro-am projects which are using combining spectroscopic with Tess data and in the past Kepler data I understand that you can't download everything but is there a possibility for targets of opportunity did you see the big grin it's an easy question there are two answers to your question one is that every three months when we turn the spacecraft round we will take full frame images the whole quite possibly the full 47 degrees field there will be needed for calibration purposes that will only be every three months I can't tell you at the moment we were discussing this in a meeting a few weeks ago how often or how many of these pictures we need but we'll certainly have those so we'll have a long sequence of regular images of the full field of view that will be available for everybody the second thing is that 8% not of the time of the telemetry so basically 8% of the pixels that we download will be available for any astronomer in the world to request so anything that's in our field of view 47 degrees across you should be able to find something that's of interest you can request that that be observed so we're expecting to be asked to follow supernovae satellites asteroids variable stars absolutely any quasars safer galaxies anything you can imagine 8% of the bandwidth that we've got available so just calculate 8% of 436 gigabytes off the top of your head that's how much we can do every day for guest observers anyone in the world to observe with Plato and wants to observe their object for 2 years bang bang bang bang continuously The introduction of this sphetroscopic analysis made setty, redundant or irrelevant now because I spent many years and keep the computer running for 6 months and downloading a lot of data but I've never heard much more about it but I was involved with that for some time but I'm just wondering whether that technique now is kind of being pushed into the sideline that's all you don't hear so much about it I'll let you into a secret the computer in my office is also running setty at home and it's been running it for it must be just after the project started that has gone into the background just because so many years and they still haven't discovered anything they have a few candidates that they've been following up but so far nothing really good the great thing is when you combine Plato and then Ariel afterwards which will follow up a couple of years behind us Ariel, the James Webb Space Telescope they'll be able to look at the atmosphere of candidate planets Plato will tell them these are the best, the most interesting targets to look at and then they will follow up with their own instruments and that actually may be a lot more successful than hoping that somebody on one of those planets has a radio transmitter and is actually bothering to beam a signal at us we'll see actually proving that there's life on a planet is not as simple as you might think but there are various indicators in the atmosphere oxygen, methane they're both very strong hints that you've got life on a planet if it's a small planet like Earth with methane in the atmosphere it's very likely you've got microbes of some kind so that may actually be the better way of trying to find life in the universe there aren't many microbes with radio transmitters not that I've met at least troublemaker in the back I think they've ignored the lesson from the solar system seems to be that not just a planet in the Goldilocks zone are good for life but maybe I see moons and things in outer planets and what about... Emil was smiling a lot during the talk he has to be worried yes I'm thinking in terms of Earthlight light of course people have got a lot more optimistic since then Titan has a huge amount of methane in the atmosphere nobody quite knows where that methane comes from one of the possibilities that has been planted and I don't know if you think this is realistic or not is that actually there's biomass under the surface that's releasing that methane methane gets destroyed rapidly do you think that is actually a plausible theory because I've certainly heard it proposed I'm not with that theory that's interesting Titan is very because it looks so much like a permitted Earth and of course the ocean worlds like Europa seems that actually most of the Galilean satellites have probably got an ocean of some kind under the surface we're getting more outrageously optimistic I'm being outrageously optimistic in one sense with Plato and I think he's going to give us some ideas in another sense the icy moons nobody would have imagined them as suitable for life even a few years ago then some guy called Arthur C. Clarke wrote an entire novel about it and populated Europa with all kinds of strange life forms and the interesting thing is he might just be right as he was with other things but I think I'll listen to him and find out how plausible that is Ariel have already come up with a target list which is suitable for amateurs to observe transits will you be looking at those stars or will you be using a target list of your own we'll have our target list because we've got our field of view and we've got to observe what's in that field of view because the controllers of the Plato satellite are the Germans in Darmstadt they are very protective of their satellites and they have announced an edict that we are not pointing our satellite anywhere else in the sky whatever we say it will be pointed at that area of the sky so yes we'll have a target list candidates and we'll be asking people to confirm the candidates in that area is there a link to this Austrian chat on your website there isn't at the moment because we're at very early days but I can put you in contact with him any more for any more hidden in the bag so we're looking for earth size planets we're looking for planets in the Goldilocks zone but we're also looking for solar systems that are stable and is there any way we can look for hundreds of billions of years but we could look for solar systems that are likely to be stable because there might be a Jupiter size planet whizzing round near the earth star planet are we close to that at all well certainly if you know that you've got a Jupiter size planet close into the star any small planets inside it are unlikely to be very stable for very long so once you've picked up the map of the solar system where the planets are you'll know quite quickly how dynamically stable it is and realistically I think anything that has a 10 Jupiter mass planet in it unless that planet is a very long way from the star or very very close in is not likely to be stable but once we know where the planets are and what their masses are you can work out what the likely stability is one of the surprises people have had looking at the stability is the fact that our solar system the planets have been wobbling back and forwards a great deal since the solar system was formed Eurasian Neptune was certainly not way out there where they are now 4,500 million years ago that's one of the surprises we've had the planets do migrate and they get closer and more distant over time because these big planets shuffle them round so that's something yes we do need to look at very carefully so anyone else one last question could we ever detect planetary magnetic fields our own magnetic field is very important to the state of the current earth that's a more tricky one I can imagine ways it might be possible to do it but it would need instrumentation very much more sensitive than exists at the moment however if you had told me 30 years ago that amateur astronomers would be taking spectroscopy with a resolution of you said 20 meters 20 years ago no professional telescope could manage that or very few professional telescopes could manage that what is possible today and what might be possible in 20 years time it's very very difficult to imagine astronomy and astronomical instrumentation come on so fast it is possible that we might be able to do it just the magnetic field split spectral lines so if you can observe with high resolution you can see the spectral lines splitting that would allow you to detect the magnetic field but you never do it with any earthly instrument now so you want to finish I was going to say try and keep Mark under control time but I think you've done an exceptional job so thank you much indeed Mark very useful and it's obviously good time thanks so much indeed and Hazel has asked me to just give a quick mention she's still selling some raffle tickets we'll be drawing the raffle just after the next talk just before the sky notes just outside I think a pound a ticket there's a variety of prizes just on the table there for you to look at so just come up to quarter two if you'd like to come back in for starting off again when Emma will be talking about her work in this system a bit nearer to home thank you much indeed so I would say sorry I'm just I'm going to use my own raffle ticket okay can we try it on this the next one after is all the other stuff's worked it's just that I've got movies embedded in stuff if they're embedded it should work it's embedded on my computer and on the memory stick it's not can we not just take the copy off your laptop that means otherwise we're not changing between you and the next presenter okay well let's try if I give you the memory stick you can see if it works and if it doesn't work it works I just don't want to have to faff about putting things back in 12 so Emma do you want which one is it oh I'll just drug that and there's one audio file I'll just go and make sure is it that presentation would you do that yeah what I'm going to do is um take off this interview yeah no spoilers hold on I'll join and get it off the screen it's fine can I just make a comment Mark managed to accidentally turn his laptop on various people were saying the sound level's gone up and down so if you just make sure the lapel mic is on it's working it was nice it was nice yeah well it's just the sound when he was walking away when he was walking away because he had a lapel mic and he accidentally turned it off so he was just going to the lapel mic so I'll give him a kicking yeah where do you do that the thing is when he got a room the voice it carries it didn't matter in the room but it's the other thing too is when people are asking questions it's not right towards the end but we do need to say to people please if you want to ask a question wait for the mic one of the problems with I do a lot of webcasts and if I'm doing something on demand I always chop the questions off for the part you need the permission just so when people come back before you introduce if you can just press the slide show button I said that for the last time so oh that's my microphone okay can you pick that up at all is that any better yes or not is that any better can you hear can we test just as well as you hearing Lepid's working is that any better thank you yes yes yes yes yes yes yes yes yes check check yeah it's it's okay yeah No, I know what to do, yeah, you just tell me to press that, it's fine. Okay, that's fine, okay. Good afternoon everybody, hello. Is it working a lot? Are we okay? Okay, thanks a lot. Thank you, excellent. So continuing a planetary theme. I've got Professor Emma Banks, she's a planetary scientist working at the University of Leicester. And shortly is the president-elect of the Royal Astronomical Society, and taking over in April. So involved in multiple high-profile space missions, exploring our solar system, including Cassini, obviously which has finished, Juno at Jupiter, VepiColombo at Mercury, and the future juice, the IC Moons Explorer, which is obviously the subject of her talk this afternoon. She actually uses data from these missions to answer fundamental questions about these diverse solar system objects. She's the principal investigator on the instrument called the Mercury Imaging X-ray Spectrometer, part of the VepiColombo payload launched to Mercury in October 2018. She played a key role in the definition of the proposals for the juice mission, and she will be working on the two of the instrument teams from that mission when it arrives in the Jupiter system in 2030. So the published approximately 120 scientific papers on solar system science and received multiple awards in recognition of her work, in particular, recently receiving the 2018 Royal Astronomical Society Chapman Medal for her research on the gas giant planets. Thank you for that great introduction, so you've introduced me, so I don't need to do that part, so I'm just going to move straight on in the interest of time. I'm going to talk about oceans, ice, and fire, the mysterious moons of Jupiter. Okay, so as you will all know, as you move out from the sun, Jupiter is the first of four gas giant planets in our solar system, and I always refer to Jupiter as the planet of superlatives, okay? So it's the largest planet in the solar system. It's about 11 times the size of the Earth, and it contains two-thirds of the mass of all the planets in the solar system put together. It rotates faster than any of the other planets, so despite its giant proportions, its day is just under 10 hours long, which is quite incredible. It takes 12 years for Jupiter to orbit around the sun, as it lies five times further away from the sun compared to the Earth. Okay, so it has the most dynamic atmosphere of all the planets, got the laser pointer, and of course it's famous for the great red spot, which you can see here, a long-lived storm in the atmosphere that's been raging for hundreds of years, possibly even more, inside which you could actually fit two to three planet Earths. It gives you an idea of the scale of the great red spot. And it's got 60 or over 60 different moons. Many of them are very small and quite faint and don't even have names, but four of them are incredibly famous. And in fact, the more we learn about these mysterious moons of Jupiter, the more we sort of change our view of the way the universe actually works. So here they are. I'm going to introduce you to the most spectacular of Jupiter's moons. We've got fiery Io at the bottom left. We've got smooth icy Europa, which you can see just there. We've got planet-sized Ganymede and we've got scar-covered Callisto. So I'm going to give you a little bit of insight into each of those bodies in this talk. And these moons were discovered just over 400 years ago, and since that time they've been studied with backyard telescopes by spacecraft en route to faraway destinations like the Voyager mission. And they've also been investigated by dedicated missions such as Galileo in orbit around Jupiter. So I'm going to come to all of that in a moment, but what I'd first of all like to do is to go back in time. I just want to show you something really fun. So as I'm sure you all know, just over 400 years ago in 1609, this amazing scientist, Galileo Galilei, was designing a telescope, designing a better telescope than was currently being used elsewhere in Europe. And importantly, what he did with that telescope would literally change the way we view the universe forever. So at the time, the popular belief was that the Earth was the orbital centre of all the celestial bodies, so the geocentric model. And what he did with his observations was to change that view. Okay, so let's just have a quick look at what he did specifically with the Jupiter system. So in the top left is actually Galileo's journal. So you can see scribblings, I can't read them, and drawings of his observations that he was making at the time. And on the right-hand side, you've got an example of the publication of those observations in Ciderius Nuncius, and that was published in March of 1610. Now, at the bottom, what I'm going to be showing you are a reproduction of those sketches. So the asterisks and the circles are actually reproductions of Galileo's drawings from those observations that he made in 1609. And just above that, you can see, hopefully you can just about see, there is Jupiter at the centre and four objects. Now, those are actual calculations, because we now understand the Galileo moons and how they work and how they orbit. Those are calculations of where those moons would have been at the time of those observations. So we can do a comparison between what Galileo saw and what we now understand from our knowledge of those bodies. And I think this is really quite neat. Obviously, I'm terribly over-excited about it. Okay, so you can see on the first night, the 7th of January, Galileo made an observation, and he noted in his journal that he was quite surprised to see Jupiter in amongst three stars that all seemed to be aligned with the ecliptic. The next night, on the 8th of January, he made a second observation, and he noted, with some surprise, that these three objects were now to the right-hand side of Jupiter, and indeed, on the next night, to the left-hand side of Jupiter. And this confused him, because as far as he was concerned, these were stars. And yet, Jupiter seemed to be moving the wrong way relative to those background stars, and indeed zigzagging across his field of view. And actually, he noted as early as this observation that he thought that these stars were following Jupiter. Okay, on the next night, I just want to point this one out, because I think it's quite interesting. You can see here that he's drawn Jupiter and two stars, and as you can see from the model prediction of where the moons actually are at that time, you can see that two of them are transiting Jupiter, and so he couldn't resolve those observations, and so he saw two only and Jupiter. I think that's really neat, talking about transits that you were hearing from earlier. Finally, on the 13th of January, Galileo actually resolves four objects for the first time. So that's really great. So now I've got a quick movie of all of the observations. He made 64 observations of the positions of these four stars relative to Jupiter between January and March in eight weeks of observations. And during that time, he actually worked out their relative sizes and he worked out their orbital distances, and he came to the conclusion that they were not stars. They were following Jupiter across the sky, and his prediction was that they were indeed in orbit around Jupiter. Now, as you all know, what he discovered and would later become known as the Galilean moons, Io, Europa, Ganymede and Callisto, and, of course, what he did was to show that not every celestial body was orbiting the Earth, found evidence to support the Copernican or heliocentric model, and, of course, as I'm sure you know, the history made him rather unpopular. Okay, so let's fast forward back in time to present day and think about, so those are remote observations, using a telescope. Mark talking about observing exoplanets. But what about if we can actually go to the body? What about if we can send a spacecraft somewhere? How much more do we expect to learn? So if we can send a spacecraft to travel through the solar system, like the Voyage mission or indeed like the NASA Galileo mission, then, of course, we significantly improve the view. So you can see here the basic outline of the Galilean moons. Let me just put the next little bit of information on. Okay, so closest to Jupiter, then, we have Io. And Io is about 3,643 kilometers across. So it's not that different from the size of our own moon. And it orbits at around 6 Jupiter radius. So just to give you an idea of the scale size of Jupiter, a Jupiter radius is 71,400 kilometers, approximately speaking. And as you can see there, the orbital period of Io around Jupiter is 1.8 days. Okay, next we have Europa, slightly smaller than Io, and at an orbital distance of just under 10 Jupiter radius and orbits with a period of 3.6 days. Okay, then we have planet-sized Ganymede, 5,262 kilometers across. Ganymede is actually bigger than Mercury. That's one of the other missions that I work on. So Ganymede is similar to Mercury in a few interesting ways. It orbits at around 15 Jupiter radius and has an orbit period of 7.2 days. Okay, and then we have Callisto, the furthest away from Jupiter. Callisto is actually the third largest moon in the solar system. Ganymede is the largest Titan in between and is 4,821 kilometers across and orbits at 16.7-day orbit around Jupiter. So why am I telling you all these numbers? I'm sure that some of you are keen-eyed and have spotted the relationship between the orbit periods of some of these moons. So you can see that we're multiplying up as we move out from Io to Europa to Ganymede. And that actually plays a crucial role in the way the system behaves. And I'm going to come back to that in just a moment. In fact, I'm going to come back to it right now. Okay, so there's two really important factors in the Jupiter system. And the first is the effect of gravity. So that's what we were just seeing there in those numbers, the orbital periods being a multiplication factor of each other. Okay, so we've got Io whizzing around close to Jupiter and then Europa outside of that and Ganymede outside of that. So for every four orbits of Jupiter that Io makes, Europa makes two and Ganymede makes one. Okay, so this is called the Laplace resonance. This is a very special resonance that the moons are in and it has a really interesting effect on the bodies. So obviously the presence of the very large planet Jupiter in the system has a significant gravitational effect on the bodies, but actually they are significant size moons themselves moving around in the system and they also affect each other. And so this resonance pattern actually produces a pushing and pulling motion on the individual moons. And we tend to refer to these as solid tides. Okay, so it's like the tidal interaction that you get between the Earth and the moon. And on Io, you might be surprised to hear that the solid tide or the motion of the surface of Io is thought to be up to 100 metres. So the interaction between Io and the other moons and Jupiter produces this pushing and pulling of the surface and again at Europa the solid tide is thought to be 30 metres and so that effect gets smaller as you move further away. Now of course this has a very important effect on the interiors of these moons and in fact provides tidal heating to the interiors of those bodies and I'm going to come back to that in just a moment. The second really interesting effect is the effect of electromagnetism. And this is one of my favourite topics, my field of expertise in terms of the gas giants is in space plasma physics looking at magnetic fields and aurora. Okay, so just to quickly describe to you the situation, as I say, Jupiter is the planet of superlatives. You won't be surprised to hear it also has the strongest magnetic field of all the planets in the solar system by a long way. And that magnetic field, we're learning more about it actually from the Juno mission but that magnetic field is generated deep within Jupiter itself and as Jupiter is rotating very quickly every 10 hours so the magnetic field is also rotating very fast. Okay, so that magnetic field of Jupiter extends out into the surrounding regions and we call this the magnetosphere. Guess what? Jupiter's magnetosphere is the largest magnetosphere in the solar system. You're sitting in a magnetosphere right now and it works in a very different way to Jupiter's. So Jupiter's large magnetosphere is rotating around rapidly approximately once every 10 hours but the moons are moving more slowly around Jupiter and so you have a magnetic field which is sweeping past the moons, interacting with those moons and producing some very interesting effects. Okay, so let's go through each of the bodies in turn. So first of all, let's think about Io. Io is the closest of Galileo moons to Jupiter and is rather bizarre looking actually when you get a really good photograph of it. I always think wonder what Galileo would have thought of these pictures from the Galileo mission, named after him obviously. And so Io is this sort of yellowy looking kind of pizza-ish type moon. It looks a bit like a rather unappetizing pizza but is covered with these dark spots and uncovered in sort of yellow material. It's actually a very young and smooth surface and as I mentioned already, it's subject to some of the strongest tidal forces of all the moons and flexing of that surface producing heat in the interior. Now, in turn what that does is to produce a magma ocean underneath the surface crust and produces active volcanoes. In fact, Io is the most volcanically active body in the solar system and these volcanoes were discovered by the Voyager flybys that took place in the 1970s and you can see the picture on the right-hand side there that was analyzed by scientists looking at this data as it was coming in from the Jupiter system and I know that when that picture first came in people were not sure, they just thought there was something wrong with a camera. You know, there was a bad pixel or something occurring that there was a bad image of Io and were not expecting at all to have captured a volcano in erupting on Io's surface. And so our understanding now is that Io has this magma ocean underneath the crust and is producing these active volcanoes. In fact, there are thought to be over 400 active volcanoes on Io and this is a little movie that was taken by the New Horizons spacecraft on its way to Pluto actually showing one of the volcanoes, Tvastar in the north there. You can actually see that is a movie of the eruption of that volcano as the spacecraft flew past, which is pretty amazing. Okay, so actually incredibly those volcanoes produce around a ton per second, a ton per second of material continuously from those volcanic eruptions. So Io moving around near to Jupiter is like having an active comet orbiting around Jupiter thinking about the amount of material that's being produced. So what happens to that material? Well, initially the material is of course neutral, coming from within Io. It's mostly sulfur and oxygen, sulfur dioxide, gas. But what you can see in these pictures here is that that material forms what we call a torus. So the neutral material is surrounding Io and as Io moves around Jupiter, it forms a path of neutral material and over time those neutrals become ionized by photoionization or electron impact ionization and produces a plasma torus. So then we have a plasma torus surrounding Io all the way around planet Jupiter and this produces some very interesting effects indeed. So first of all we have Io moving along its orbit around 17 kilometers per second and we then have Jupiter rotating around with its magnetic field at around the orbit of Io at about 75 kilometers per second and so we then have a situation where we have effectively a conductor, Io and its plasma torus, sitting in a very large, strong magnetic field which is rotating around and this actually produces a perturbation along the magnetic field lines which are connecting Io to Jupiter and that perturbation is carried by an electric current that then connects Io to the upper atmosphere of Jupiter. So it feels a bit like science fiction at this stage but I promise you it's not. So there's just another little sketch of what I'm talking about. We've got this plasma torus going all the way around where Io is orbiting around Jupiter and then where these magnetic field lines are passing through Io and we have a conductor moving around relative in a magnetic field to generate a really interesting interaction. Let me show you what that looks like in Jupiter's upper atmosphere. So this is a picture taken by the Hubble Space Telescope, one of our favorite telescopes to use. We do lots of observations of Jupiter and Saturn in ultraviolet wavelengths specifically looking for auroral emissions. So this is Jupiter's northern auroral emission and what I want to point out first of all is on the left hand side you can see a spot and you can also see a trail coming behind and that is actually the footprint of Io. So that's the interaction between that conducting body moving in a magnetic field that's set up an electric current which then is communicating with the upper atmosphere of Jupiter. Okay. So now I've just put in a picture of the Earth and you can see Earth's auroral oval as well and actually that's sort of roughly to scale so you can see that you can fit approximately two to three Earths across Jupiter's northern auroral zone which again is sort of mind-blowing. These are enormously powerful, guess what the most powerful auroras in the solar system by a thousand times stronger than the Earth's and take up a huge amount of latitude in Jupiter's polar region and I can just point out a few features. So I pointed out Io already and we also have two more spots which are relating to Europa and Ganymede and we then have what I've labeled the main auroral oval and it's not quite an oval so we can talk about that but you can see on the left hand side it's quite smooth you can see what looks like a fairly clear auroral oval and then on the right hand side it becomes a complete mesh you can ask me about that later I'm not going to have time to go into that and then within that main auroral oval region we also have something which has been labeled the polar emission it's very imaginative labelling here this is because we don't really know what causes the polar emissions and we still actually don't know this is one of the things that Juno is currently studying and we are actively working on but in order to describe to you how the main auroral oval works which is actually still relating to Io I'm just going to take a moment to describe what the magnetosphere actually is so a magnetosphere is formed as a result of the interaction between the sun and any planet that has a magnetic field an internally driven magnetic field so we have intense heat in the upper layers of the sun's atmosphere which causes the gas from the sun to become ionised and then to flow continuously into space and that's known as the solar wind and the solar wind carries with it the sun's magnetic field and so the solar wind and the sun's magnetic field moves out throughout the solar system and interacts with any planet that has its own magnetic field and what it does as it approaches a planet with a magnetic field is to squash the planet's field on one side and then stretch it out into a long tail on the other side now the Earth's magnetosphere which we understand pretty well is driven by a process known as magnetic reconnection and that process takes place at that first point of contact between the solar wind and its magnetic field and the planet's magnetic field and that reconnection process drives a series of events and the manifestations of that interaction is the Earth's aurora so if you've seen the Earth's aurora that is solar wind magnetosphere interactions in action now Jupiter doesn't quite work in the same way although it does have aurora which look on the face of it relatively similar to the Earth's Jupiter's magnetosphere as I've already mentioned is the largest in the solar system and in fact just as an interesting point it's thought that that solar wind interaction with Jupiter's magnetic field is thought to extend all the way to Saturn's orbit one of the Voyager flybys it was thought that maybe Saturn was even within the magnetotail of Jupiter and that changed the sort of interaction that we were seeing between the solar wind and Saturn at the time okay so Jupiter's magnetosphere is dominated by rotation as I've already mentioned so Jupiter is rapidly rotating and the other important fact for Jupiter is the fact that we have this comet which is orbiting around Io we've got this plasma source so what happens next okay so we have a ton per second of material that's being continuously put into the Jupiter system so if you add mass to the system then actually in a rapidly spinning system it actually wants to move outwards okay so the plasma associated with Io actually moves continuously away from Jupiter and forms the sort of red bit of the cartoon you can see there which is known as the magneto disk now as it does that stretching out as the plasma moves outwards away from Jupiter it stretches the magnetic field line so you can see I've drawn some solid white lines those are the magnetic field lines of Jupiter and as the plasma is moving out it's stretching out Jupiter's field and it's still all spinning around or trying to once every 10 hours so this is an enormous scale size that we're talking about here and this plasma or magnetic field is trying to keep up well funnily enough it finds that quite difficult the ionosphere is helping out by communicating a torque actually along the magnetic field line to the equatorial plasma to keep it spinning but it can't quite keep that process working and so eventually what happens is that the plasma starts to slow down compared to that rotation rate and we call that the breakdown of co-rotation so it's a fancy way of saying that it can't keep up okay and what that does is it actually causes the magnetic field lines to bend backwards so they're sort of dragging behind as they're trying to spin around and if you know anything about electromagnetism you'll know that if you bend the field you're going to generate a current system so now we've got a situation where the field is dragging behind you generate an electric current system that's the dashed lines in that diagram and we have upward directed current outward directed current at the equator in the red region and then back towards the planet and it goes across in the upper atmosphere and it's actually where you can see that red arrow pointing it's actually that upward directed electric current down going electrons that are being accelerated into Jupiter's atmosphere that it's actually thought to produce that main aural oval okay so this is sort of mind-blowing I think I'm completely biased because you can probably see it at the bottom it's the subject of my PhD thesis so that's why I'm so enthusiastic about it okay so we have this process this strange situation whereby we have a plasma source Io in a magnetosphere Io's orbiting around close to Jupiter Jupiter's magnetic field is spinning around and the interaction between those produces the brightest aurora in the solar system so for the person who asked the question about could measure magnetic fields remotely one way you could do it is to look at evidence for emissions associated with aurora like radio emissions or you know for example okay and people are actively thinking about doing that okay so little Io the tail wagging the biggest dog in the solar system okay let's move on to Europa okay so Europa has this stunning surface geology I think this is one of the most amazing pictures of Europa again taken from the Galileo mission it has a smooth icy surface not many craters which means that it's young it's being replenished and it's thought that there is an ocean beneath the icy crust and you may be aware or you may not be aware that in fact the first evidence for that subsurface ocean actually comes from magnetic field observations so that was discovered by the Galileo mission and as the spacecraft move close to Europa the magnetic field instrument the magnetometer on board the Galileo mission measured changes in the field direction which could not be explained by an internally driven magnetic field at Europa or indeed by Jupiter's background magnetic field I'm sort of wrapping it up in a few sentences it was many years of work to get to the point that it was understood that those magnetic signatures are actually the signature of an induced magnetic field okay so the idea is that the subsurface ocean underneath that icy crust is conducting capable of conducting electric currents and again you have Europa moving around in a larger strong magnetic field which is also varying in time and it's that variability in time that allowed the understanding that this was an induced signature sort of flip-flop back and forth as Jupiter's field rotated around kind of hard to imagine and this is the amazing lady who did the work Margaret Kibbleson she won the gold medal of the RES this year was presented with the medal this year she turned 90 this year she's an absolutely amazing woman I have a huge amount of admiration for her and she's still working on Europa Clipper which is hugely exciting for her she discovered these signatures from the Galileo mission and now she's still working on the next mission to go back to Europa and find out more okay so it's thought from those magnetic measurements that Europa's ocean is ten times deeper than any ocean here on Earth so maybe a hundred kilometers deep that is incredible I get my first year tutorial group to work this out what does that imply for the volume of water it implies that there could be two to four times as much water in that subsurface ocean than there is here on planet Earth and so as you can imagine tidal interactions producing warmth that enables the liquid the water to remain liquid and we also wonder or think that Europa's ocean may be in contact with a silicate floor and that could explain some of the markings that you see on Europa's surface it could be organic materials and hence we then start to think about the opportunities that might exist for habitability of that subsurface ocean we know that here on Earth we find life where you really wouldn't expect to find life in the deepest parts of the ocean where there is no sunlight okay so moving on to Ganymede Planet-sized Ganymede for me is one of the most fascinating of the Galilean moons because it seems to sort of have everything it's got these really diverse features so it has the largest number of impact craters of any planetary body in the solar system and it's also thought to harbor a subsurface ocean and in addition to that it also has its own magnetic field so a magnetic field that's generated internally to Ganymede so Ganymede subsurface ocean is thought to be a little more complex than Europa's and possibly in different layers I've seen multiple versions of this diagram with ice layers and water layers and what have you but actually what we really need to do in order to understand what's lurking underneath Ganymede's icy crust is to actually put a spacecraft into orbit and once you have a spacecraft in orbit around Ganymede then you can start to understand the details of how the mass is distributed throughout the interior so the observations again from the Galileo mission again Margaret Kibbleson made the discovery using the magnetic field data first of all measured this small relatively small perturbation in the magnetic field which is an induced magnetic field an induced current system associated with a subsurface ocean but then over time the measurements also indicated that there was a stable component to that magnetic field so one that didn't flip-flop depending on where Ganymede was relative to Jupiter's magnetic field and that indicated that Ganymede actually has its own internally generated magnetic field so the only moon that we know in the solar system that has an internal magnetic field now if you then take a moon with its own magnetic field and put it in a larger magnetic field you end up with a miniature magnetosphere within a magnetosphere so that's all good stuff so there you can see we've got little Ganymede which although it's big large Ganymede, planet-sized Ganymede in Jupiter's magnetic environment and Jupiter's magnetic field interacts with Ganymede's and produces a magnetosphere okay now I'm hoping this is going to work so these are I just want to play this to you because I think it's just one of the best things ever this is Galileo plasma wave measurement so we've got a frequency time spectrogram so this is the data that I'm going to play to you okay so this is not actually measured at audible wavelengths but if you just shift them then you can listen to them okay so a little bit of artistic license but I think it's worth it okay so this magnetic field and magnetosphere was really understood by using these measurements let me start playing it it might be quite loud so brace yourselves so that noise is the place where the boundary of magnetosphere and now you can hear the rising frequency to get close to Ganymede and the field strength gets stronger you can hear the particles rotating around those field lines and their frequency of change can move through a stronger a weaker magnetic field and here there's really high pitches and then they start to come down as the spacecraft moves away and the field okay I might get stopped I just love listening to it so Margaret Kibbleson referred to that as Ganymede singing magnetosphere so you could hear the particles singing on the magnetic field lines okay Ganymede also has its own rural display in its weak atmosphere measured by the Hubble Space Telescope and the footprint that I mentioned to you earlier finally we have Callisto which is well another fascinating object in its own right it's a heavily created ancient surface it is thought to have an undifferentiated interior so that's pretty unusual and that's based on gravitational measurements so we need to find out more about Callisto to really understand its interior and it is also thought from the magnetic observations again that it might have a subsurface ocean in the water everywhere in the outer solar system you can also see Valhalla here I'll try not to fall off the stage you can just see the sort of central point of that impact crater there and you may be able to work out multiple concentric rings it's one of the biggest, it is the biggest impact crater in the whole solar system okay so as you can imagine all of this water so excluding Io because there's lots of lava and volcanoes and definitely not a holiday spot so then we have Europa, Inganimida and Callisto which are all thought to have subsurface oceans and so if you're interested in thinking about the potential for habitability whether that be in the past or in the present then these ocean bearing worlds are obviously of great interest so what we need to do is go there and make more detailed measurements and this is where juice comes in the Jupiter icy moons explorer a very strange acronym which is a long story in itself I was lucky enough to be invited by the European Space Agency to be on the team of scientists that defined the mission so it's absolutely one of the highlights of my career so far and we worked very hard on the mission of bringing it to go to the Jupiter system and specifically to go into orbit around Ganymede as a focus of that mission and there is also a NASA mission called Europa Clipper which is going to go and focus on Europa okay but juice will not only look at Ganymede, it will also look at Jupiter and so there's a huge amount more that we can learn about the system important facts are talking of patience juice is going to be launched in 2022 the mission was accepted in 2012 and it will be hopefully launched or it will be launched in 2022 and because I'm really impatient for it to arrive at Jupiter in 2030 so we have to wait a really long time if you're a planetary scientist you have to be extremely patient and we're going to get opportunities to do a couple of flybys of Europa and a couple of flybys of Callisto and Ganymede before being the first mission to go into an orbit around an IC moon okay so I think I've basically mentioned all of this, this is just a sort of timeline of activities where we will focus on Jupiter itself at the first part of the mission moving to studies of Europa we've got 10 Callisto gravity assists which will give us a fantastic opportunity to study Callisto and multiple visits of Ganymede before we finally go into orbit around Ganymede and at the smallest orbit we will get to within 500 kilometres of the surface of Ganymede so you know just wait for those images and information that we will get from that mission now you've already heard about the habitable zone so I don't have to spend a lot of time on this but as we heard earlier we're typically interested in where liquid water on the surface but what I hope I've shown you is that you can have liquid water underneath the surface so unlike looking for Earth-like planets that we were hearing about from Plato this mission is looking at habitability in the more general sense so we're interested in these deep habitats we have them in the Jupiter system we also have them in the Saturn system we've got Enceladus spewing water out into Saturn's magnetic environment we've got Titan which is thought to have a subsurface ocean so it gives you a different perspective on this concept of the habitable zone and there's my sort of link to what our mission can contribute to our understanding of exoplanets I mean absolutely fascinating subject and it's changing all the time in terms of the numbers of planets that we have confirmed and the nature of those planets and we've been hearing a lot more about that today but my argument has always been that our own solar system we can go to and we can actually go to and make close up studies of these moons and I think we should really exploit that opportunity of studying our own backyard as it were okay so there's just an overview of all the different science that we're going to do we're going to look at Jupiter we're going to look at these coupling processes that I've told you about gravitational and electromagnetic and look in more detail at the nature of these subsurface oceans which exist at these moons and our justification slide at the end of our presentation when getting this mission selected was that we felt it was the next logical step in our exploration we have the discovery of the Galileo moons from Galileo back in 1610 we've had the first visits from the voyage emissions those amazing spacecraft that are still going still giving us new information about our local environment we've discovered that there are deep habitats here on this planet which are able to survive without sunlight and exploration from the Galileo mission at Jupiter, the Cassini mission at Saturn and discoveries of potential water worlds in extrasolar systems and so now is the time as you can tell this is my pitch but it's okay because the mission is happening it was selected yes so now is the time to go back and really characterize these bodies and learn the next level of understanding and discovery about the subsurface oceans so I always think of Galileo I think of how far we've come and I wonder what he would think if he knew that this was the kind of thing that we were now able to do so thanks very much for listening thanks so much indeed Emma that was very good thank you thank you wonderful we've got about 10 minutes or so are you okay to ask some questions if I may because this is being videoed and being live streamed in actual fact if you get selected to ask a question if we can wander around and give the microphone to you because whilst we can hear you in the room it's actually a little bit difficult for people elsewhere so have we got any I'd like to take the microphone over thank you thank you very interesting have you any idea of what the temperature of the oceans might be that's a very good question no I I don't think that we have any in the Jupiter system I don't think we have any direct measurements as yet the Hubble Space Telescope has actually recently confirmed that there could be plumes at Europa similar to the plumes that we have at Enceladus so that's been a fairly recent discovery and I'm trying to remember the numbers from Enceladus but I mean cold is the answer really cold no I think to be honest with you I think until we have measurements from orbit and specifically with infrared spectroscopy that we won't really be able to say much more until then but the nature of those sub-servitations definitely not my field of expertise is very interesting like how how does the water remain liquid how could you possibly have layers of ice and water and ice I don't know the answer to that but the gravitational measurements give us an indication of that distribution of mass and so again I think when we have data from orbit, multiple orbits going around and around Ganymede we'll be able to build up that picture gravitational field with remote sensing ultraviolet infrared and that will really help us to get close to that but I suspect you know if we'd like a direct measurement then we need we need a future mission to Europa or Ganymede or both that would actually put a lander down onto the surface and I think that well I know that that's already what people are thinking about for the future the next next logical step but with all these complicated magnetic fields on Ganymede and Jupiter and so on and these likely conductive oceans I would expect there'd be lots of electric currents in these oceans which is something that we've got no analogue for on earth so and I would thought that would have a bearing on whether they could support life do you have any thoughts about that? That's a good question in those terms if I'm honest with you the currents are not particularly strong actually I mean I'm trying to think of the numbers for the current that's flowing between Io and Jupiter for example is about a micro amp per meter squared so they're not particularly strong currents I mean they are in space plasma physics terms so that's a similar current strength actually to the current of the earth that produces the aurora but whether that would have any significant effect on habitability I think is a very good question I don't know I like the idea of getting our first G2Ts to calculate the I'm going to nick that a few but I was just wondering is it still thought that the metallic ocean at the center of Jupiter this is responsible for the magnetic field and do we know how it's done? Good question and very relevant because the Juno mission which you may have heard of is a current NASA mission which is at Jupiter now and is in an orbit which is specifically designed to study very close to Jupiter as in nearly close to Jupiter a few thousand kilometers above the cloud tops at closest approach in each of elliptical orbits around Jupiter and what we've learned so far from that mission is that Jupiter's magnetic field is much more complicated of course than we had previously thought so the idea is that the postulation is that the magnetic field is generated by liquid metallic hydrogen highly pressurized layer of liquid metallic hydrogen within Jupiter somewhere and the question was where? Okay and so one of the things that Juno wanted to work out was could you work out where that generation of the magnetic field was? The results so far suggest interestingly that there may actually be two different depths that the magnetic field is coming from so when you look at Jupiter's magnetic field it's like no other planet in the solar system actually I would say at this point having studied magnetic fields at planets interesting thing about our solar system is that each planet's magnetic field is really just unique they're not like each other and so if we think we understand how magnetic fields are generated in general I think what we're learning by exploring the planets up close is that perhaps need to rewrite our theories our ideas. Anyway to go back to your question it's thought that that process is quite likely to be happening at Jupiter but there could also be another layer where a magnetic field is being generated and the reason that that's thought to be the case is because we see the details of Jupiter's magnetic field you know we think about it being a dipole the sort of classic thing you do at school with your iron filings and your dipole you know bar magnet and you get your loops of field and that's what you think a planetary magnetic field looks like which to a large part it does not at Jupiter it looks so different and it has the next one up is a quadrupole and then an octupole and then it goes up and up and up in order and complexity and you can think of that as being sort of multiple loops of the field and we see so many high order fields at Jupiter which are strong and it's in the mathematics you'd love it it falls off as 1 over r to the 4, 5, 6, 7, 8 as you go up in complexity but you see those higher order terms which implies that they must be generated quite close to the top of the atmosphere that's remarkable we've been talking about the magnetic field and it drives me that water has got proton and if you've got protons in a powerful magnetic field you can have euclid magnetic resonance now for euclid magnetic resonance you need radio waves but Jupiter is also a powerful producer of radio waves and also if you have an orbiting spacecraft it could bombard the moon with radio waves so I'm just wondering if there's any potential here to use NMR not only to find out about the nature of water in the planet but given that organic compounds also display NMR you could use it to detect organic compounds very interesting so one of the instruments on Juno I'm going to sidestep the question because I don't know the answer but one of the instruments on Juno is looking for water in the atmosphere and it's a microwave radiometer and it's the first type of instrument like that and it works at I think six different wavelengths and it has these arrays on the side of the spacecraft that are all different sizes that are measuring different frequencies coming from the atmosphere indicating different layers so there is already the technology to try to get those water and ammonia actually for Jupiter measurements from within the atmosphere but I don't know the answer to your very interesting question from your powerful magnetic field it's a crucial thing it is a crucial thing, yeah, absolutely and it's a very powerful magnetic field yeah, on the time frequency plot that was behind when you were playing the singing ionosphere towards the right hand end there appeared to be a harmonic structure which was not present initially there were multiple bands at intervals I've seen that in acoustics Petra yeah, well you see a lot of bias do you know what's going on there? I mean it will either be so if you can just about make out there's like a peak in the emission that you're seeing there so that will be the closest approach to the spacecraft to Ganymede and where the field is strongest and where the plasma frequency has peaked as you get to the strongest magnetic field and then it's falling off and then you're seeing multiple frequencies now what that would normally indicate and I can't say for sure that that's what that is what that would normally indicate in space plasma physics would be the presence of some sort of wave particle interaction and then of course you can have multiple frequencies present and harmonics present and we see that a lot actually in the magnetic field studies of the Earth so it's kind of interesting to see that Ganymede's magnetosphere is really quite sort of miniature version it might be more like the Earth's magnetosphere than like Jupiter's magnetosphere but with some interesting differences in the sense that Jupiter's magnetosphere is driving Ganymede's magnetosphere and unlike so the Sun's magnetic field interacts with the Earth's magnetosphere and it changes direction it moves around Jupiter is the planetary magnetic field so it's always pointing in the same sense and so it's like a continuously driven system so it's a quite unique situation so when we get there the first part of the orbit of juice is actually to really study the magnetosphere in more detail so the close 500km altitude orbit is to look at the surface and to get the magnetic field and the gravitational field of Ganymede itself and before that we have an elliptical orbit where we will actually be crossing through all of these regions of interest where we have this interaction and where I imagine we'll be seeing a lot more of that interesting data and listening to Ganymede singing Thank you Thank you Thank you Thank you very much again Can I ask you before you I can ask Emma to draw the raffle ticket It's very exciting Just one There are three things so we've got an orange ticket It's an orange 47 Who's the lucky winner? How do we get one? 6 6 How do we get a ticket? This is Ganymede That means I'm released Don't think it's mine It's a pink number ticket You can This is fixed This is our treasurer here You're not uncancel are you? You're not uncancel This is very suspicious Do I need to speak louder? 1, 2, 3 Can you hear me on that? Shall I just get going then? Right This is the kind of squishy bit at the end of the meeting where I'm going to entertain you for about 30 minutes with some pretty pictures and some interesting stuff of what's happened in the sky over the last few months and what's going to happen over the next few months So hands up everybody who's seen Venus so far in this apparition So a pretty large number It's a fairly far south declination at the moment so it's kind of scurrying along but it will be becoming easier to see later This is a lovely picture of three planets here So you've got Jupiter down the bottom here Venus and Saturn is just up there and of course the crescent moon so this was 29th of December so just at the end of last month On the odd occasions we get clear sky in the evening just go out and look to the west very low down Venus but it'll be getting higher and I'll come back to that in a minute So normally in these sky notes we start with this fascinating object at the centre of the solar system sorry Lynn This is of course our sun which is Jupiter may be the biggest of everything planet wise but obviously the sun is the biggest in our solar system and it generates all of its magnetic field and solar wind and everything but it manages to do all of that at the moment which is a bit of a shame if you're into solar observing but of course you can use hydrogen alpha and there have been a few prominences recently this rather nice one by David Strange a couple of days ago coming out from the limb of the sun and of course all of that material that comes out of the sun the solar wind interacts with our magnetic field which is definitely very puny compared to Jupiter's but produces some very nice displays and Gordon Mackey up in Scotland always manages to get some fantastic photographs I like showing them at the Christmas meetings they're just so so good this is polar star trails with an aurora thrown in for good measure and he's actually illuminated that can in front with an LED light just to get a really really nice effect so astrophotography can go all the way from really deep scientific and technical images of the sky to something like this which I just think is an absolutely wonderful image just capturing the whole beauty of the night sky if you look at this closely there is a satellite trail in it and I'll come to that in a minute as you might imagine but I won't say anything nasty about Elon Musk because he can get quite angry and he might be watching a live stream anyway, so we still get reasonably good aurora even though the sun's not very active at the moment we're still getting a lot of good aurora this is one of those ones that Dennis Buzinski managed to photograph from up in Tarbott Ness in the north of Scotland Dennis often complains about the light pollution from his aurora they kind of distract him from the most important thing he should be doing which is actually imaging comets and I know Dennis is watching at the moment so all these pretty pictures of aurora but he does get some wonderful aurora I've been up there many times I've never actually been lucky enough to see one from his observatory but he certainly gets very nice views of the northern lights of course you can only do that when the sky is reasonably dark and we have our own huge natural source of light pollution but which can also be a really interesting object to observe but for various things that I'm going to talk about a little bit later the Geminid, Meteor shower for instance the moon is a real problem so just looking at the dates on here we have a new moon coming up on Boxing Day 26 and that actually corresponds to an annular eclipse of the sun and we have full moon coming up on January the 10th which corresponds to a penumbral eclipse of the moon we also have the Geminid Meteor shower coming up on December the 14th very close to the full moon in December which is a bit of a pain for us meteor observers but I'm always amazed by the kind of images that people can get I get even more and more amazed by the images that Damien Peach can get although he does have access here to a one meter telescope so this is the chili scope that he now uses so here's Paula Paula 14 inch Celestron obviously he's not really cutting the mustard anymore so he's using this one meter telescope and basically this is now moving remote observing from deep skies to planet as well so as I understand it essentially there's a PC there in chili that does all the video collection and he does all of the processing locally in chili on that machine using remote desktop so you don't have to bring the gigabytes of video back but this is a really extraordinary picture and it kind of I remember when I was a lad the kind of picture of the century was a picture taken by the Lunar Orbiter spacecraft which was looking obliquely over Copernicus and just the details you can see in these ramparts here is quite extraordinary really amazing stuff so yeah this is the eclipse coming up on Boxing Day anyone going to see this one thought probably not there are a few people who do actually travel even to see annular eclipses so this is one of those eclipses where the moon is near Apogee and of course at this time of the year the sun we're near Perihelion so the sun is almost as big as it can get and the moon is quite small so it doesn't fully cover the sun so this is an annular eclipse it starts at sunrise and the Arabia crosses the UAE and goes into Oman and then heads out over the Indian Ocean here and eventually ends up in the Pacific so there will be a few people who go to see this most of them will be situating themselves somewhere around Oman or around there to get the ring of fire at sunrise there's also lunar eclipse annular eclipse nothing really exciting the moon doesn't go into the earth's umbra but it does fit in the penumbra this is visible from the UK on the day to full moon in January, January the 10th in the evening so about 7pm if you go out and have a look at the full moon it won't be quite as irritating as it normally is it'll be a little bit fainter because it's in the penumbra of course the big event that's happened recently is this all the mercury transit a goodly number that's not bad given how rubbish the weather was over the UK I think people have been pretty lucky in managing to get cloud gaps and managing to pick up the transit it's the last one I think till 2032 is that right I think when the next one is so we were lucky to actually get to see it and we've had some really nice pictures submitted to the BAA I've got time to show all of them but I just wanted to run through a few this really nice sequence from Nick Quinn to Ingress showing mercury moving on to the disc of the sun and you really realise when you see mercury against the sun what a small planet it is I mean it was just over 10 arc seconds in diameter moving on to the face of the sun and of course that's as large as mercury pretty much ever gets because we're seeing it in line with the sun there nice picture here from Richard Petrie a little bit later as it had moved on to the disc on a wheeler managed to get this with an aircraft flying across the sun and mercury there and that's the kind of really nice demonstration of the perils of imaging the sun in the south-east of England of course if you use hydrogen alpha you can get a little bit more detail you can see granulation on the sun here so this is a really nice image and then this one of course on the cover of the current journal Ella Bryant's picture showing the prominence and mercury on the disc at the same time so imaging lots of really nice images not so many visual observations but as you'd expect Paul did this drawing from I think with Pete Lawrence you were weren't you well that's possibly true but you actually managed to get did you actually see Ingress or did you see that was your first view very nice view and good to have a visual representation of this transit I thought I'd stick this one in on a claim that her plane was fully on the disc here is not quite fully on the disc but I've used this in a couple of things I've done with schools to do some kind of physics lessons about the sun's 150 million kilometers away mercury about 100 million and if you know the length of an MD-11 which us geeks know that that is you can work out how far the plane was away it's about 35 kilometers away and about 30,000 feet so there you go, bit of geometry there and then Gary Gauthrup sent this one through and I thought oh he's got the image upside down until I realized that actually this was taken in Florida so in Florida he could actually see the egress so this is I think about the only image we have on our website which shows the egress so mercury went through its transit and then it done a brief display in the morning sky so if you get up in the morning sky you'd have seen and you had a good eastern horizon you'd have seen mercury looping up it moves so faster and the sun it's gone now but this is our current picture of the week on the BAA website this is Leo Atz's picture of mercury this is an image of an object that's just over six arc seconds in diameter I think it's just extraordinary that you can get that kind of resolution on an object of that diameter I think it's one of the most amazing pictures of mercury that I've seen actually if you wait a little while to the end of January mercury will do its little loop again so you have an opportunity to see it in the evening sky but the main thing in the evening sky that we're seeing at the moment of course is Venus Venus coming up from the horizon moving gradually north as Saturn is moving in the opposite direction and they pass each other I think December the 10th, 11th is the closest if you look on the BAA website that's one of our observing challenges at the moment so if you do manage to get some nice images of Venus and Saturn passing each other please send them in put them on the members pages of the BAA it's a good way of displaying what you're doing and also sharing your work with other people a time lapse would be quite good to do as well but of course that would need you to have these guys every evening for the next two weeks I think that's probably fairly unlikely Saturn of course is now moving towards conjunction again this is an amazing image that Damien sent in taken with that one meter chili scope which shows extraordinary detail again but Trevor Barry's image is not bad as well I mean that's really good but we've pretty much lost Saturn now as it moves towards conjunction the same with Jupiter so really it's Venus coming up over the next few weeks there will be a good planet to observe in the evening sky and we've had some pretty good pictures sent in this one from Peter Meadows and this one from Tim Hames when I first looked at it I thought it was Buffalo but there's not many of those roaming free for sure they're actually sheep but you could believe they were possibly Buffalo there are two planets that are fairly well visible actually in the sky in the early to late evening that's Uranus and Neptune and this is a rather nice image of Uranus taken by Chris what would be it's about three and a half arc seconds I think something like that Uranus so again amazing that you can actually get such imagery with amateur telescopes now there has been a little thing with Neptune recently and I do apologize to the professional astronomers who are in the audience but there is a website called the transient name server and this is a website that professionals use to announce discoveries supernova that kind of thing and there's a professional survey called master which announced a discovery of an 8th magnitude transient object in Aquarius and this being professionals it wasn't just one person it's basically half a university who appears the author list now you'd have thought that one of this huge and no doubt very esteemed group of people might have checked what this 8th magnitude object in Aquarius was anyone want to have a guess Neptune so Roger very politely sorry Robin very politely posted on the TNS Neptune question mark and of course it was so there you go as far as I know the master team haven't posted any follow ups or no apologies or anything you may remember that a couple of years ago there was an event where a guy in South Africa I can't remember his name off the top of my head was in the Lagoon or something wasn't it as a bright transient there so you know at least he was quite good about it he got a certificate actually anyway well indeed yes so there you go at least as amateurs we're allowed actually to post they trust us as amateurs if you're registered to post to the TNS we're not allowed to post to the astronomers telegram as amateurs because we're obviously not you know trustworthy enough and that's where the discovery of Mars was announced anyway Terry Evans picture there of Neptune, Triton and fire query so if you do discover anything bright in Aquarius do just check it's not a planet Urban Laveria probably got there before you did anyway in terms of discoveries you may not be aware of this because it hasn't been that well publicised so far but the BAA has started up a new system to distribute alerts to people we used to have an email system but technical reasons that was withdrawn we now have a system called BAA alerts you can go to the website you can sign up for that there hasn't been much traffic yet but the idea is that section directors can use it to announce anything that might happen to be coming up in the sky as an alert system so I recommend you go along and register for that right in terms of things near the Earth the ISS is up there at the moment we've got some good passes of the ISS this is a really good one which happened about an hour ago but there's good passes tomorrow as well and of course yesterday our friend Elon Musk or a few days ago launched SpaceX CRS-19 which is going up to rendezvous with the ISS today tonight you may have been able to see both of them go over together by tomorrow night they should have actually docked but if you can take images like this and these amazing images by Chris Hooker taken with a telescope and a high speed camera show amazing detail on the space station as it comes over and you might think that that's a really, really you need really advanced equipment to do that but these images I think from a couple of years ago but these are from Tim Burgess what these are is he had an eight inch Celestron with a Canon camera operating in video mode on the back and he just manually tried to follow the space station and every now and again managed to get some good video of it and it's amazing what you can see even with that kind of very simple approach right so the next bit is where I've got to be a bit careful about Mr Musk and his associates you will recognize I think these objects these are the first launch of 60 Starlink satellites they were sent up in May this is just after they've been released about a day after they've been released by the rocket so the rocket they're launched on Falcon 9 has a payload capacity of about 24 tons which means it can launch 60 of these 180 kilos satellites up into space so SpaceX plans are that these will be used to provide internet connections around the world the first plans are basically to fill up low earth orbit with about 4,800 of these things and then move into higher shells as well that's going to involve a lot of Falcon 9 launches and it's going to involve a lot of these spacecraft being up in orbit and as amateur astronomers worry about is what that's going to do to the night sky now it is true that these things are only a problem when they're actually visible in twilight but the trouble for us at our latitudes is twilight lasts most of the night through the summer so we'll be seeing them a lot this is Sierra Tololo this is then visible in the night sky there not that long ago couple of weeks ago the second batch went up so bear in mind there's only two batches now so this is the Falcon 9 launch couple of weeks ago this is another 60 of those satellites going up there's going to be another 160 odd launches something like that of this to fill up Leo with it and these are all the spacecraft so each of these is about 350 kilos they get pushed off and then they spread out in orbit they have ion thrusters that allow them to raise their orbits to their operational altitude and we're already seeing the results of these in a lot of astronomical images this is what our meteor cameras saw a few days ago this is William Stewart's camera Ravensmoor this is Planfield so you can see them moving there this is the next one will be my camera in Chelmsford you can see them moving up here and then Alex Pratt's camera which you'll see in a sec you can see them moving across the sky so these objects are going to become more and more of a problem and I think as astronomers there's probably a lot we can do about it seems to be pretty much free for all as to what people can launch the practicalities of making these things darker is very difficult given the thermal requirements that the spacecraft has so I think from an imaging point of view we're going to have to rely on more and more clever software that can somehow detect and remove these from our images but it's not just visual stuff, radio as well this is a meteor radio detection using graphs this is William Stewart's detection of about 60 of these starlink satellites as they went across so I'm afraid they are going to become more and more of a problem and we are going to have to somehow adapt to deal with them professional observers have got problems too but in many cases they are further closer to the equator so they have less of a problem than we do far north but unfortunately having had to battle with terrestrial light pollution I think we now have a situation where we are going to have to battle with these spacecraft as well another thing we have to battle with is the media I get all of my astronomical news from the Daily Express as I'm sure we all do this is an example of actually relatively sane reporting talking about an asteroid pass although it did say it was going to come dangerously close dangerously close being 6 million kilometres but David Swan got a really nice time sequence of it how good are you as observers can anyone spot the asteroid on this sequence I'll give a raffle prize to anyone or one of the old raffles see I can't even find it now there it is ok so as an example of how things in the media have just reached a state where you can't believe anything you read in the media one of the things as an engineer I find incredibly annoying is that as engineers and scientists we've spent hundreds of years trying to come up with an internally self consistent of units for measuring distance, velocity, volume whatever which the media can't use everything has to be in the size of double decker buses but this goes to an extraordinary thing this is talking about an asteroid it says even at the lower end of the estimate the space rock is believed to be 9 times as long as a queen size bed and about 3 times taller than an average giraffe so I'm not sure that helps really I know vaguely what a queen size bed is but there aren't many giraffes that roam the streets of Chelmsford so thank you daily express for that now come on to something much more serious variable stars whoo, cheers from the audience so there are really two nice binocular variable stars that are worth having a look at over the next month or so this one, chi-signai which is very well placed in the evening sky in Cygnus at the moment and it's coming up to its maximum so it'll probably reach about 5th magnitude something like that at maximum, that kind of thing and that's due in January so that's a star that's definitely worth having a look at making some estimates of with binoculars and there's another one which we all know very well our Corona Borealis which is a little bit more needs a bit more effort at this time of year because it's a morning object so it needs you to get up fairly early in the morning and here it is it's just recovering from its fade but it's still reasonably active if you look south at this time of year of course we see all the winter constellations Orion, Gemini lots and lots of interesting deep sky objects in this region and then sort of above us as well we've got Cepheus and not only do we have variable stars but we have variable nebulae and I'm just going to mention a couple here that are worth looking at the Aldarion's nebula which is illuminated by the variable star pvcfi is currently looking rather sorry for itself rather rather faint but definitely worth keeping an eye on and then the other one, McNeil's nebula which is in Orion just south of M78 it's pretty much disappeared all together so again another variable nebula to keep an eye on to see when it might come back and of course there are some really lovely deep sky objects in the winter this picture of a rosette nebula I think is particularly wonderful because it was taken from Stanmore in Middlesex it shows that with the kind of even with the kind of light pollution that we have to deal with if you have the right techniques and the right filtering and the right equipment you can get amazing pictures but this picture of Graham has an amazing amount of the outer detail of an object that we all think we know very well M42 but which every year I still have a go at imaging because every time I look at M42 with maybe a new piece of equipment I see something new meet yours, we've got the Geminids coming up on the 13th, 14th of December they've already started but the peaks around the 13th, 14th of December unfortunately they are at their peak pretty much at the time of full moon so there will be a problem this year but this bit of video here is a Geminid from a couple of years ago taken with my Sony Alpha 7 camera and a nice fast lens and there are now so many different video systems looking at the skies for meet yours that we're collecting a huge amount of data on meet your showers but even if you just want to do visual observing that's still important to do in the case of the Geminids you'll just have to make sure that you try and get the moon out of your field of view behind behind something it'll be quite high up unfortunately in fact on maximum night it's in Geminai so it's about as bad as it possibly can be the alternative is the Quadrantids which are around in early January moons conditions much better for those the Quadrantids have a very narrow peak but if you do get clear skies on January the 4th and that's at least long enough after New Year's Eve that you should have recovered by then get out there and have a look at the meet yours so then sort of coming to the end I haven't mentioned comets yet and that's because unfortunately as comets section director I haven't actually managed to serve up any really bright comets unfortunately no comets like these two these are we recently started putting archival images in our comets section archive so these are scans of material from a long time ago the one on the left there is the famous comet from 1957 Comet Aaron Rowland and the one on the right is Comet Vest from 1976 so suddenly we don't have any comets quite like that the brightest comet that we do have around at the moment is a comet that was discovered by Pan stars in 2017 and it was a long, long way out when it was discovered and it was about 20th magnitude and it's been brightening slowly it's coming into perihelion next year in May but it has a big advantage for us that it's circumpolar at the moment and it's actually passing through a number of constellations we're very familiar with so it's currently in Perseus and it heads very close to the double cluster which you can just see sort of north of Perseus there so very close to the double cluster towards the end of January so quite a nice potential photographic target it's not hugely bright but it's something you can pick up with relatively small instruments it's probably about 9th or 10th magnitude at the moment visually it'll probably peak maybe 8 or so visually discrepancy between what visual observers see and what images get but it's got a nice tail this is a movie I did of it a few days ago and in fact again to see if there are any really good observers in here there's an asteroid moving in this frame as well can anyone see it? yeah so there there it is so that's an asteroid that I think was about 18 million kilometers away or something at the time but I'll just run quickly through a few pictures this one from Peter Carson I think it must have been one of the last ones that Peter did before abandoning the observing site in Southend and moving to the south of Spain it's past some really nice deep sky objects so this one from Martin Novely here as it was passing by which open cluster was this M36 M36 I can do the comets it's just these kind of weird stationary star patterns Dennis Pazinski an image from up there and then Steve Arnold has now started taking some really good images of comets and Dave Eagle here a color image so keep an eye on that comet through the winter it'll be well placed for us all to be moving slowly definitely something to have a go at finally on the comet front there's this one which I wrote a short article for in the last journal this is Comet Borisov this was discovered by Gennady Borisov this guy here using a I think a 0.3 meter very fast Hamiltonian telescope so especially designed for comet discovery it looked like a fairly boring comet when it was discovered but when it's orbit was computed it's actually got an eccentricity of over 3 which means it's actually come in from outside of our solar system so this is the second only confirmed interstellar visitor we had we had Uma Muir a year or so ago which was more asteroid all this is definitely cometary it's on an orbit which is diving down through our solar system it's just about coming to perihelion now it comes to perihelion in December and it's reaching about 15th magnitude it's in crater though at the moment so you need a more southerly telescope to get some imaging of it but really an amazing object and the fact that amateurs we can get images of objects like that you know lumps of ice that have come from other solar systems thanks to Martin Nobley this is an image from yesterday using the I telescope so unfortunately I can't promise you any bright comets but if we did rely on the media to tell us about bright comets this was another great one this is the daily mirror unparalleled in its science coverage huge comet will fly past Earth this week and there's a chance you could see it so this is this was a few months ago and it's about a comet called 168P at the time that this article was written the comet was about 20th magnitude so just to wrap up I thought I'd put up this rather nice Christmassy picture and ask if anyone could guess what this actually is serious it is serious so this is a golden macchi picture of Sirius taken with a lens that he just wobbled around so whilst Sirius was sitting there twinkling and scintillating in the sky you see all of the colours of Sirius so I think this is really neat as a kind of just a clever thing to do with a camera system so that's our Christmassy picture so thank you very much happy Christmas to everyone safe trip home don't forget that comet and don't forget all of the other things too but Venus and Saturn conjunctions and the Gemini too so happy Christmas everyone see you next year if I can just hold attention just a few thank yous before people leave again IOP Paul Hardacre is sitting just on your left my right Catherine Mackenzie working with Hazel proud to set up everything for us Simon Clark, Red Hughes David and I.T. team Ella McConnell main point of contact for today Fran, the catering team Mark Kudger, Emma who said I had to leave to catch and of course Nick and Davis and David Boyd and Peter for the BIA stand the raffles were donated by Simon Bennett from Widescreen Space Rocks and Kristen Nebula and the BIA team for overseeing registration and general help and you the audience for coming along and so on so as Nick has already preempted me wishing you a safe journey home and a season greetings and I hope Santa brings what you want down the chimney with his hope he doesn't break the safety of the camera when he arrives thank you very much David you