 I've never had a countdown before, so thanks. It's appropriate for NASA webinar, right? Okay, well, hello everyone and welcome to the September NASA Night Sky Network member webinar. We are hosting tonight's webinar from the Astronomical Society of the Pacific in San Francisco, California, but we are strewn all over the country from coast to coast tonight as we are many times. We're very excited to present this webinar with our guest speaker, Dr. Paul Abel, the Chief Scientist for Small Body Explorations at NASA's Astronomaterials Research and Exploration Division at the Johnson Space Center. Welcome to everyone joining us on YouTube. We're very happy to have you with us. These webinars are monthly events for members of the Night Sky Network. For more information about the NASA Night Sky Network and the Astronomical Society of the Pacific, check the links in the chat that we'll put in there in just a few moments. Before we introduce Paul, here's Dave Prosper with just a few announcements. All righty, hi, folks. Okay, let's see, I'm just gonna get the, oh, sorry, I gotta switch to, there we go. Okay, serious announcer voice. All right there, just a couple of quick announcements. I just wanna keep it quick. Our pins are being manufactured, very exciting and when they arrive at my doorstep, hopefully by early October, I'm gonna send out the announcement with all the details so you can order these awesome new outreach awards pins for all your folks work in 2021. And just so you know, just your club just needs to add two reports to your events for the year. We will always love it if you add more reports and we encourage you to do so, but we realize that many folks are still operating under many restrictions. So just a couple would be handy. Thank you very much and we can help you out with that. If you need, that's what we're here for. We all have a couple more fun announcements. So as we come into October, we are having the Global Moon Party on October 9th from six to 9 p.m. Eastern with folks from the NSN International Observe the Moon Night and the Explorer Alliance. And the schedule and links to join will be in our next newsletter and there's a little bit in our past as well. But also if you want to, you can subscribe to the channel and get on alert when we're live on YouTube. And I'll put the link to both the YouTube event and everyone in the chat, right? And the details and schedule as well. And one more quick announcement is that the ASP is having their 133rd annual meeting and astronomy educators and communicators of all stripes are invited and the early bird registration and abstract submissions are both the deadline is October 6th. And for more info, you can go to astrosociety.org or the link in the chat. And YouTube, you're gonna be in there in a second. Alrighty, that is it for me. Thank you all folks. All right, thanks, Dave. So for those of you on Zoom, you can find both the chat window and the Q&A window in your Zoom menu bar on your desktop. Please feel free to greet each other in the chat window or to let us know if you're having any technical difficulties. You can also send us an email at nightskyinfo at astrosociety.org. If you have a question for our guest speaker this evening, please type it into the Q&A window that helps us to keep track of them and not lose them, which is always a really good thing. So I'm gonna hit the local recording here. Welcome to the September webinar of the NASA Night Sky Network. This month, we welcome Dr. Paul Abel to our webinar. Dr. Paul Abel is the Chief Scientist for the Small Body Exploration within the Astro Materials Research and Exploration Science Division at Johnson Space Center. His main areas of interest are physical characterization of near earth objects via ground-based and spacecraft observations, examination of NEOs for future robotic and human exploration and identification of potential resources within the NEO population for future in situ utilization. As a geologist, it's always fun to see where we can go dig up more minerals and find interesting rocks. And so it sounds like Paul is actively interested in finding some of those rocks for us. So thank you. Abel has been studying potentially hazardous asteroids in near earth objects for over 15 years and is an investigation team member on NASA's Double Asteroid Redirection Test, or DART mission, which is what you're gonna find out about in just a couple minutes here. So please welcome Dr. Paul Abel. Thank you very much, Brian. Okay, I'm going to share my screen here and let's see if we can get things rolling. Let me know if that's coming through, okay? Looks great. Okay, get started. All right, well, thank you very much, everybody. And this presentation is you and for you. And basically this is all about planetary defense and defending earth from hazardous asteroids, which is one of the things that we are very interested at NASA and one of the things actually that we are charged to do by the presidential administration. Obviously this is a big effort. This is just to give you an idea of the number of organizations and the number of people that are involved in the Double Asteroid Redirection Test. Lots of lots of university agency industry and government support. So it's a big team and we also have international partners as well with members from Italy. And I'll talk a little bit about that later. Okay, just a little bit about the presentation outline. Go over some recent impact events. A little bit about introduction of asteroids. What are they and where do they come from? So this is a very high level overview. Some of the potential impact consequences talk a little bit more in depth about the dark kinetic impact mission and what some of the objectives are. And then talk about a companion mission that we are actually working with our European Space Agency partners it's the Hera Rondev mission and then sum up with some closing thoughts. And I think as Brian said there will be some time for questions as well. So this is a little dramatic but there's an event in Russia and Chelyabinsk 2013 caught everybody by surprise. This was one of my best days ever, actually not really. It was a really, really busy day for me. And it was one of the things that just happens and we didn't expect it. And it was a very bright and dramatic effect. Lots of energy. Fortunately, no one was killed but there was a significant number of people hurt. And a hundred people went to hospital but over 1600 people were injured as a result of the shockwave. So this is actually a video of what people saw on the ground. So there's that big contrail and that's the moment the shockwave actually hits. And so you can see these people looking at the contrail, reacting to the shockwave. And that was a result of the media only about our bull light I should say about 20 meters across coming in in excess of speed of about 40,000 miles per hour and detonating at altitude of around 29 kilometers. And there's some video here just showing you the effect of the actual shockwave even though it exploded relatively really high up, it's still propagated down to the ground and cause significant amount of damage. Notice this, these people have seen the flash. They see the contrail, they're looking outside. This is an office. And then the shockwave hits about 90 seconds to a minute later or a few minutes later and people are shocked. There's some damage and they don't know what exactly is happening. Watch what happens to this door. Again, blown over from the result of the shockwave. So there was lots of video. I encourage you to go online and look at this. You can see what happened to these two people. They're enjoying their morning. This was about half past nine in the morning. And a lot of people thought actually it was a terrorist attack or some type of an attack and they weren't sure so they rapidly evacuated. So damage estimated was about 33 million US dollars. The initial meteor weighed about 12,000 tons. It punched a hole in the lake. As you see here, the diameter of the hole is about six meters and they actually recovered a sizable fraction, the terminal piece, which is about 1,400 pounds and it was recovered. Lots and lots of pieces were collected by members of the public and it turned out to be a ordinary contract type of object, but heavily shocked. So that was interesting. And again, that's a topic of a completely separate talk. But anyway, just to give you an idea of what the actual meteorite was associated with this particular asteroid. So again, just to give context, this is for what we're dealing with here. Here's the earth looking down on the solar system. We have asteroids, the asteroid belt in between Mars and Jupiter. Most of the objects that come at us that we are interested in, about 95% of the objects that are near earth objects come from the asteroid belt. So we focus more of our attention on this particular area. There are obviously the leftover bits, the rocky remnants of planet formation and interactions in the main asteroid belt send material both inward and outward. And it's the inward material that we have to worry about. Lots and lots of objects. The diagram or the animation that you see here on the lower right hand side is looking down on the solar system. The red, orange type objects are the near earth asteroids. The green are those main belt asteroids. So we focus more of our attention obviously on the near earth asteroids for planetary defense. But keep in mind there's reasons to do so for science exploration and then resource utilization as well. So just to give you a sense of scale of what we're talking about, here's earth, here's moon, here's dwarf planet series just to give you an idea of scale. Zooming in now, there's series on the far right and four Vesta on the left and then some main belt asteroids and that tiny, tiny dot right at the bottom which is about 500 meters across is the asteroid Itacaua that was visited by the Hayabusa spacecraft about a decade ago, 2007. More recently, we have looked at asteroids and we've had spacecraft go to two asteroids, serendipitous, we've had our own mission of Cyrus Rex and we had a Japanese mission called Hayabusa too. I was fortunate enough to be involved with both of these missions and these were science missions. These weren't necessarily planetary defense although there's lots of planetary defense knowledge learned when you go to these particular types of near earth objects. So on the left hand side, it was the asteroid Rugu. It's about a kilometer across and it was visited by Hayabusa too and then Bennu on the right, which is about half the diameter, about half a kilometer and it was visited by a Cyrus Rex. Just to give people a context, Hayabusa too is successfully returned and we have samples of Rugu in the laboratories being analyzed right now. We have some particles here at Johnson Space Center. We expect some more samples to come back in December timeframe and we're making arrangements to receive those. Cyrus Rex samples, Cyrus Rex doesn't come back until about two years from now, September of 2023, but stay tuned and it's looking good. The spacecraft's still healthy and so in two years we're gonna be very happy with lots of asteroid samples here at JSC, at Johnson Space Center. Okay, so everybody I think is familiar with impact craters. One of the more famous impact craters we have in the United States is the Beringer Meteor Crater in Arizona was formed about 50,000 years ago by a approximately 50 meter diameter metallic asteroid. Remember I said Chelyabinsk was an ordinary chondrite. It was a rocky, this asteroid that hit in meteor crater is metallic. The crater is about 1.2 kilometers in diameter. It's about 180 meters deep. It's located near Winslow, Arizona. I recommend that if anybody has a chance to go and visit it if you haven't, it's well worth the trip. Just make sure that you take plenty of water because it does get very hot out there and especially inside the crater itself if you get to go near it and around it. Anyway, you can see from the diagram on the right the meteor crater is centered there. This is the estimated sort of energy or blast zones that were associated with this particular crater. So out to 10 kilometers, there was a fireball. Then at 24 kilometers, you had more of a blast plus heat and out further, you have hurricane force winds up to 40 kilometers. So this is sort of gives you an idea of the type of devastation that these objects can have even though they're relatively small, they do tend to pack a punch. So here's the same scale, but this is centered over Washington DC with Virginia and Maryland for reference. And again, just the same contours of the fireball and other devastation regions. So you can see over a metropolitan center, small asteroid would definitely cause a lot of damage. So right now at NASA, what our plans are is that we are working to stop, think of ways of beans of stopping ease in some of these smaller asteroids that are relatively hard to detect and prevent them from hitting the earth and not just the United States, but all over the world. That's one of the things that we work on. We also do this by doing exercises at Planetary Defense Conference. So we had a Planetary Defense Conference in 2019 in College Park, Maryland. And this was just sort of an example of what could happen if you had a 60 meter asteroid impacting over Manhattan. And lots and lots of energy released, very more powerful than some of the nuclear weapons that were dropped in World War II. And you can see some of the unsurvivable and orange zones where things get harder and harder. So red is unsurvivable. As you move further out, it gets a little bit easier, but still would be very hard on the type of population and a lot of structures and damage done. So again, one of the reasons why we're doing this. So here's a plot that I'm showing in terms of why this is a global concern, as I mentioned, do this not only for the United States, but the entire world. And this is fireballs that were reported from 1988 to now. This chart was the most recent event was September 6th. And so this is a result of high altitude air bursts coming in and hitting the atmosphere from small asteroids. And as you notice, they come in from all sorts of different directions and they hit everywhere across the planet. There's no one preferred orientation, no one preferred timeframe. And Chelyubinsk is this object you can see up in the biggest red dot. That was the example, 20 meters. It was about 500 kilotons of TNT, so actually 440 kilotons of TNT. And these type of objects, fortunately don't happen very often, every few decades to centuries. But again, we wanna be prepared for these type of things. Especially Tunguska-cyber object, that was the event in 1908 in Tunguska, Siberia. And that was a much larger object detonated much lower to the ground. So Chelyubinsk for reference was about 29 kilometers. Tunguska, a little bit bigger object penetrated deeper into the atmosphere and detonated about five to six kilometers and wiped out 2,400 square kilometers of forest. And then of course, people I think are very familiar with the Chelyubinsk-sized dinosaur killer that happened about 65 million years ago and caused a major global level extinction event. So here's the hazard by the numbers, just to give people an idea. Again, this is not to scare people, but this is just to sort of give people an idea of what we're dealing with. So how big, ranging, talking about four meters all the way up to 10,000 meters, and then how many per year you can see, how many of these types of impacts that we could probably expect, and then how bad things would be. Our atmosphere is actually really pretty good at protecting us. Even Chelyubinsk, even though it was a 20 meter object, the atmosphere did a pretty good job, although people still got hurt. So we still have to be mindful that even relatively small objects can cause a lot of damage. And so the bottom section there of this chart shows us exactly how we're doing in terms of finding these types of objects. So for the really large ones, they're much easier to detect and find, and we're doing pretty well on the 1,000 meter and 10,000 meter objects. We're almost at completion, which is good to know because those are the objects that can wipe out humanity on the planet. Getting further down though, when you start looking at things that are in the 160 meter range and smaller, we have some work left to do. So again, this is where we're concentrating our efforts in looking at some of the smaller objects that are more numerous and statistically more likely to cause a bad day in the timeframe of interest. So here's our former NASA administrator. This is at the Planetary Defense Conference and this is the statement that he made and it really is protecting the planet and defending life as we know it on our planet Earth. So we do have a Planetary Defense Coordination Office at NASA. The Planetary Defense Coordination Office is centered at NASA headquarters. And we have various centers that liaise with headquarters and we have different roles and responsibilities. So there's the search, detect and track, that's probably the first pillar you have to see the object coming and detect it. Know that that actually is a hazard. Then you have to characterize the object, figure out is it really something to worry about or is it gonna explode harmlessly in the atmosphere and then plan and coordinate what you're gonna do about it and then mitigate and whether you actually do something about it with a spacecraft mission like Dart or not. So again, find the hazards and then defend against them. And this is where Dart comes in as you see which is the first Planetary Defense demonstration mission that we're talking about doing. So here is a little bit about the mission just sort of a cartoon. Our launch window opens up November 24th, 2021, goes through February 15th of 2022. It's actually a really large launch season, which is good. It gives us lots of flexibility to make sure that we can launch on time. We did, we were going to launch a little bit earlier but we had some COVID impacts which prevented us from completing but we were able to make this secondary launch window which will still have no change to our overall objectives of the mission. But the Dart mission and the Dart spacecraft, the target is a binary asteroid. It's the DITAMOS system. So the primary object is about 780 meters. It's called DITAMOS. It rotates once every about 2.26 hours and we are going after the 160 meter companion which orbits around it once every 11.92 hours and it's called dimorphos. And the time of impact is going to be September, late September, early October of 2022. That date will be fixed once we know the actual launch date but it's gonna be right around that timeframe. The double asteroid redirection test mission is involves two spacecraft. Basically it's the Dart spacecraft. It's about 676 kilograms. It's traveling about 6.6 kilometers per second and it's gonna hit into dimorphos as a test of the kinetic impact. Writing along with it and then deployed about 10 days prior to impact is the Italian contribution which is the Ledecia Cube which is the light Italian CubeSat for imaging of asteroid. And so that is gonna help us characterize the actual impact itself. Some of the ejecta and what actually happens to dimorphos and possibly even DITAMOS. So that's a very important perspective to have so we can actually see what we did and how well we did. In addition to that, we have our earth-based observations which are at the time only gonna be about 6.8 million miles away, 0.07 AU from the impact location. And so we're gonna be able to leverage lots and lots of ground-based observatories and also space-based observatories. We're gonna try and use Hubble as well to see what we can determine about the Dart impact and into dimorphos. So here's Dart at scale. Just to give you an idea, again, Dart is 676 kilograms. With the solar panels rolled out, it's about 19 meters. And so when we hit, it's a cross-section of 19 meters. Just to give a sense of scale, there's some other objects there, the Arctic Triumph Statue of Liberty. Dimorphos is 163 meters. And compare that to the Eiffel Tower and the One World Trade Center and then Didimos there again. So just to give you an idea of sense of scale, so it's a very small spacecraft moving at a very high speed. The asteroid is relatively small at 160 meters, but we're still gonna be able to measure the effects of this kinetic impact test. So here's our eyes. This is the Draco instrument. So basically, Dart has one instrument, Draco. It's a basically telescopic camera that actually homes in on the asteroid system first, then picks out dimorphos and then goes in to hit. We'll get some information, obviously, from the Draco instrument. But as I said, the Lechicube smallsat that will be deployed prior to the impact will actually tell us a lot of information about the impact itself and actually more information about dimorphos. So one of the things that's really interesting about this, which is basically exciting in many sense of the word, is that we don't really know too much about the object we're gonna hit. We do have some ground-based information prior of the dimorphos system. We know, as I said, it's a binary. We have some radar in it. So we have a radar-shaped model. We have light curve information, so we know how fast things are rotating. We have a rough estimate of the size of dimorphos, but we really don't know too much about dimorphos itself. Nor do we know what the surface is like or the internal structure. We have an idea of the meteorite type. It's similar to that ordinary chondrite type of meteorite that I mentioned earlier with cellulence. But again, nothing is certain. So that's why it makes it a bit exciting. So we don't really know what we're gonna find and we don't know what it's gonna look like. Pretty sure it's not gonna look like a dog bone, but there's lots of different options of whether it's gonna be more seroidal, is it gonna be top-shaped like dimorphs itself, what we see from the radar images, or is it gonna be sort of oblong or does it have any other type of features? These are all things that are gonna be really interesting to try and figure out. So this is sort of giving you an idea. So the spacecraft is moving incredibly fast, right? It's 6.6 kilometers per second. So things happen very, very quickly. And so 60 minutes out, an hour from impact, we actually see dimorphs for the first time. We see the system. And then about four minutes prior to impact, we start to resolve the secondary and actually hone in on it. Two minutes out, we get a bit closer and now we're really focused on dimorphos. And then it's not until 20 seconds where we get our sort of our last set of images where we get the highest resolution we have, which we think is gonna be about 50 centimeters per pixel to understand what the surface is gonna be like. So things are happening very quick. And just so you know, this image on the right here, the last 20 second image, that's from the Hayabusa spacecraft image at Ida Kala. So the spacecraft has to be very autonomous and has to do things very quickly in order to hit it. And that's one of the things when you were talking about planetary defense and especially with the kinetic impact, things have to be done autonomously and under very, very tight time constraints in order to hit because you're moving at such high speed. Believe it or not, 6.6 kilometers per second is considered relatively slow for something that we'd probably do if we had to do something operational. We'd probably have to do maybe do twice the speed. But again, this is just a demonstration mission on a well-known characterized system, not necessarily De Morphos is well-known, but the system itself is well characterized. So this gives you an idea of just the general orbit and gives some timing. So we have Earth in blue, we have dart launch and then we have the encounter. And you can see why we picked this particular time period encounter is because of the proximity to Earth at the time. So this is what allows us to use our ground-based systems and near-Earth space systems to actually observe. So it's a really fortuitous encounter and we picked this. So here are our requirements. And so the first thing of course is number one is we gotta hit the asteroid, right? I mean, that's sort of a no-brainer. We need to hit the asteroid. In order to understand how well we hit it, we wanna be able to change the binary orbital period on De Morphos. So we need to cause a greater than 73 second change in the orbital period of De Morphos. And in fact, what we're gonna do is we're probably gonna slow the orbit down because we're gonna be hitting De Morphos head on with this particular orientation. And step three there, we've gonna measure the period change to within 7.3 seconds before and after impact. That will help us inform how much energy we've transferred to the object and determine how much momentum. And then hopefully in combination with some of the observations we get from Luchy Cube and some modeling that we're doing is we're gonna measure beta and characterize the impact site and dynamics. So knowing how the asteroid responds, how much material is thrown back, what we call ejecta, that's important to know. And that also enhances the amount of momentum, the amount of oomphs that is transferred to the asteroid. So this is the ideal target. Again, here's the original orbit. We're going around, we're gonna see it from the lower left hand side from Earth and then Dart is gonna come in and smack into dimorphos. And we're actually going to hit it head on. And there's Luchy Cube that we'll see and characterize the event and also dimorphos after the fact. And then it will take a bit of time to relay the information. And then hopefully we'll be able to determine a new orbit which will slow down. So a couple of reasons for doing this is one, it's a well characterized target. It's in a binary system orbit. So we can characterize this very well from the ground. And also it's representative of a type of object in terms of size, the 160 meters that we're interested in being able to try and deflect. Seeing as those types of objects, if they did come in and hit the Earth, would really give us a bad day. So here it is again, just the complete show and it just emphasizes the type of information, the type of demonstration mission that we're doing. So we're doing lots and lots of observations. We've done lots and lots of observations. We continue to do so to help understand the system. A lot of people, I think, because you're astronomers, you will know a lot of these facilities. And so we have facilities all over the United States and also all over the world that are helping out, trying to characterize the system, refining orbital periods, refining vibration modes of the binary, characterizing the system to a high degree. And of course, come around the time of impact, we'll be doing even more ground-based observations and space-based observations to try and characterize the system and actually see what we can see as a result of the impact. So this is just to give you an idea of, again, binary measuring the binary orbital period and you can see these little dips, the brightness as the asteroid moves in front of and behind the primary, you can see the change in brightness. And so we've got a baseline measurement of that right now. And then after the impact, we will be able to see how much that has changed over time and that will give us some indication of how well we've actually transferred the energy into it, which will then give us more confidence in how we can do this in a real case, in case we have to do it. Again, this is a demonstration, we practice, we wanna practice this, we don't have to do it right the first time when things are really counting, when people are counting on us and we have to do it right. So you practice musical instrument, you practice plays, you practice sports, and planetary defense is no different. So I mentioned beta before, which is actually a momentum enhancement. So when you run into an asteroid and you just have no ejecta and you just run into it with a spacecraft or you run into it with something, you'll get a momentum transfer, but you won't get any increase. So if you have an impact here, you transfer momentum and the asteroid is diverted a little bit, but that's beta equal to one, right. So when you have an asteroid impact, however, and you have moderate ejecta, right. So now you have some ejecta coming back. That ejecta acts as a little exhaust or rocket thrust as well. So material is flung back. So in this case, you can get enhancement from the actual impact. It's the same speed of impact, but the situation has changed because for whatever reason, the object is producing more ejecta from the similar type of energy. So your momentum enhancement is now double. And then of course, if you get a really energetic ejecta, lots of material is flung back, you can get ejecta's beta factor of four. So much more in what we call momentum enhancement. So what we're trying to do is not only prove that we can hit the asteroid, but try and understand how much of this beta factor that we may get. And it'll be very interesting to see, do we get a beta one? Do we get a beta of two or four? Or in the odd case, do we get a beta that is less than what we expect? We don't think that's gonna happen, but again, this is one of the reasons why we do this test. And this is important knowledge to know because we'd like to know how hard we have to hit an asteroid if we're actually having to deflect it. Keep in mind, all asteroids aren't made the same. Lots of different compositional types and lots of different shapes and lots of different internal structures. So again, this is our first test and first data point of this particular kinetic impact demonstration. So here's one of the sort of ideas of when I talked about internal structure and beta. And you can see some of these modeling runs that have been done by my colleagues using supercomputer models. So the box on the left, there's no porosity. The object is solid and the beta value is a certain value. The one in the center has a little bit of micro porosity. The beta value decreases a little bit, funnily enough. And then the rubble pile, loosely held together material, the beta value is changed again and a little bit higher. So the takeaway from this is that as far as our understanding goes in terms of computer models, the porosity, the internal structure of the object and the material composition actually do matter. And so this is something that, again, we're trying to figure out and understand if we have to divert a hazardous object. So all this, just so you know, this is part of a larger strategy for planetary defense. We actually are guided by the National Near Earth Object Preparedness Strategy and Action Plan. This came out in June of 2018. It has five goals. Three of them are much more relevant to NASA. The other two are as well, but the first three, detection tracking and characterization, modeling and information integration, and then deflection and disruption mitigation are well inside NASA's purview. And then of course, goal four is increased cooperation with our international partners and then strengthen and exercise impact protocols. That's basically FEMA and Department of Homeland Security and we work with them as well. But Dart fits right in here. This is our again, our first test of planetary defense and it is not a disruption mission, it is a deflection mission. And I can answer questions about whether it's later, whether it's best to deflect or disrupt. But right now we're talking about deflection. Some of the other missions that are coming up related to planetary defense, the one on the left is the Neo Surveillance Mission. This is a mission that I am also involved with. It's a space-based infrared telescope that's gonna be put at the Sun Earth Lagrange one point. So it's between the Earth and the Sun and it's looking outward using infrared to pick up asteroids and helping us find those smaller asteroids that we've had trouble finding from the ground. In space you can operate 24-7 and infrared is really good at finding asteroids, especially cause they only emit sunlight reflected off them. So using optical means is difficult if they're small and dark. Of course if they're small and dark in infrared you can detect them much more easily than optical means. And this mission will probably launch in the 2025-2026 timeframe as it stands right now. Also involved with the European Mission helping out with the HERA mission. So this is a mission that's gonna be launched in October of 2024. It is actually going to the Didymus dimorphos system and it's gonna characterize the impact crater and figure out what we actually did to the dimorpho. So although it gets there a little bit later but it's part of ESA's space safety and security program. And it has been approved and it looks like it's gonna move forward. So it's really good news about that. So this all when we talk about DART and we talk about HERA, this is part of the IEDA which is the asteroid impact and deflection assessment international cooperation team as you will. This is how we cooperate. We have DART which is going to intercept and hit the asteroid dimorphos in 2022. And then HERA will rendezvous with the system and characterize it in 2026. This is just a, I give you an idea of the HERA mission scenario. Again, launched in October of 2024. Has a couple of year cruise. It has some framing cameras on it. So cameras to do some investigations in CubeSats, laser altimeter and infrared camera and also a spectral imager to characterize the asteroid. And it connects some investigations, deploys CubeSats and investigates the target for about six to eight months and maybe possibly have an extended mission. But the whole idea is to try and figure out characterize the dimorphos and see what we actually did to it with DART and then test out some other technologies, especially with the CubeSats that will be deployed around the system to investigate the dimorphos and dimorphos. Okay, this is a video. Just to show you that this is the double asteroid redirection test. It's a neat video. It just shows you the spacecraft being deployed. It's launched on a Falcon 9. These are the rollout solar arrays that are being deployed. That is the Draco cover coming off. So the camera. There's Digimos and dimorphos and Earth orbit. And here comes DART and ready for our impact deflection test. There's Leachacube being deployed probably about 10 days prior to impact. And you'll see Draco there acquire the target and come in for a successful impact. And that's NASA's first planetary defense mission. And with that, I will take questions and I appreciate your attention. Thank you very much. All right, well, thank you very much. This is really great. We do have a number of questions. If anyone else has any other questions, please make sure to put them in the Q and A window. So if Paul, I don't know if you want to show yourself here, but that would be great if we could show. Yeah, let me do that. Let me just figure out what's going on here. Stand by. Am I, are you seeing me now? No. Not yet. How about there? There you go. There we are. Had to find the right button. Okay, so a long time ago, Carl asked a question and maybe this is the point of this, of trying to figure what this out. So Carl asks, is the impact method did you deter NEO's the most effective? Yeah, so that's a good question, Carl. And it is one of the most effective methods we have. There's also the nuclear option. Again, a lot of it depends on the type of object and the situation that we're under. We'd really like to test out the kinetic impact. We know how to run into things at high speed. We've done that and demonstrated it with a deep impact mission, if you remember that. That was a spacecraft that went in and hit a comet, right? And so we're able to do that at relatively high speed. We wanna be able to do this for planetary defense. When you start talking about nuclear weapons in space, people get very excited. That's not to say that we wouldn't use them if we actually had to. But those are usually reserved for what we call last minute measures. If you don't have any choice, if the object's really, really big, then maybe you'd have to use a nuclear weapon. Or if you figure that maybe the time is so short that you don't have any option, but to try and disrupt it, you can't deflect it effectively, but you're trying to break it up into smaller pieces, again, so that not as much energy gets penetrated through to the Earth's atmosphere and down to the ground, then that might be an option. But right now, what we're looking at is the kinetic impact. There's a few other esoteric techniques that we might try, but this is the one that we're trying first. And then we'll see how this goes and then go from there. All right. And so related to deep impact, we had a question from Gregory kind of asking about the comparison. Now that we know a little bit about what you're looking for with this. And so he's wondering, were you able to measure a beta for the deep impact? And then about the injector, was there more or less about what was expected for that collision? So deep impact was a science mission. It wasn't planetary defense. So, but the question is relevant and it's a good question. Deep impact was like, the comet was really large. We're talking a couple of kilometer diameter comet. And the projectile that went into it was just a few hundred kilograms again, a little bit smaller than Dart. So think of like a small insect hitting a jet airliner at high speed. Really not too much that you're gonna do it. In fact, the comet actually overran the projectile from the spacecraft. What was surprising was the number or the amount of ejecta that came in. They were hoping to see the crater as they flew by, but there was quite a bit of ejecta that came up because the comet was relatively unconsolidated material. And that obscured the impact crater. So there was no real beta to determine from that. Just the energy associated with it wasn't enough. But for Dart, because we're hitting something as a little bit smaller, it's 160 ish meters, we're gonna be able to measure a beta with our ground-based systems and then have Hera go in and then refine that estimate later on maybe a few years later. All right, we have a couple of questions about thinking about the impact on dimorphos. And so Eileen asked, couldn't hitting dimorphos change its orbit so that it either hits diramos or perhaps changes the system gravitational interactions and thus changing the primary asteroids orbit itself? Right, very good question. So another reason why we chose this particular near earth asteroid is number one, it's safe. So what we're gonna do to this particular asteroid is if we hit dimorphos, which we plan on doing and hopefully we're successful, it's not gonna change the heliocentric orbit of the system at all, right? If anything, it's gonna be so minute that there's no hazard to earth. We've done all the modeling and we'd have to do a lot more energetic things and especially to the primary in order to do that. And this is completely out of the realm. But the question about changing the orbit of dimorphos, you know, we are gonna do that, but we're just gonna slow it down. We don't think we're gonna send it spinning into diramos or have anything happen like that. The energies involved again are relatively small and modest. It would take a lot more energy to do that. And in fact, if we tried to do that, we'd probably end up disrupting dimorphos before we'd actually cause a significant change in that orbit related to diramos. All right. And I just had to say that Arnold had a very similar question about do we have any idea of the movement of the larger asteroid if you hit the small one and that sounds like it. It's gonna be really, really, I mean, we're gonna look for it, but it's gonna be really hard to detect. I don't, we don't expect any significant change. All right, so let's see. Let's find another one. So Suzanne asks, and maybe you address this in one of your graphics, how do these asteroids compare in size to the larger ones like Ceres, Vesta, or Pallas? Yeah, so Ceres, Vesta, and Pallas, I tried to show that in the original introductory remarks just to give people a sense of scale. Ceres is really large, right? So Ceres is a dwarf planet. It's roughly a thousand kilometers across. Vesta's half the size, it's 500 kilometers. When you get down to some of these near-earth asteroids that we're talking about, we really are looking at things in the hundreds of meters range. The dinosaur impactor is thought to be around 10 kilometers, right? Based on the crater that we found in the Yucatan. And so those objects, we have got complete. We don't see any of those that are a hazard. We know where all of those are. The one kilometer and up, we've got about 90, 95% of those guys nailed and don't see any of those as a hazard. But it's the objects that are in that sort of 500 down to 50 meter size range that we're really trying to concentrate on right now. And as you get down to smaller size ranges, you get down to where objects can still cause considerable amount of damage and there's lots of them. They're also harder to see. So if you're big, you're easier to see. If you're small, you're harder to detect. So we really wanna try and find the smaller population to retire the rest of the risk. We think we're pretty good at global effects, making sure we don't have anything sneak up on us that will give us a bad day. We still have a bit of work to do, but it's more the regional and the city size guys that can wipe out those areas that we're trying to focus on right now. All right. So here's a question about the spacecraft. Alan is wondering, was the spacecraft mass increased to enhance momentum transfer? In other words, did you add significant, I guess, dead mass to the spacecraft just specifically to increase that? We did not. There's the mass of the spacecraft. As you know, putting mass on spacecraft is expensive. Mass is that you cost your spacecraft by how massive it is and how much oomph it takes to throw it out into space. So we need to use a Falcon 9. We need to use a launch vehicle that's appropriate for our particular test. We could have added mass, but the amount when we looked at it, if we added any extra mass, substantial mass, it really wouldn't change much in terms of our objectives or our goals. We'd have to develop a whole new different type of test and then use a bigger launch goal. And so then all of a sudden, your cost of your mission increases dramatically and without much benefit. So again, keep in mind this is just the first test. We're trying to see what we have from this particular mass, 676 kilograms, that's 6.6 kilometers per second and see what we can get as a result of this particular test. That's not to say that in future tests, if we do another kinetic impact, maybe we'll ump up the mass a bit just to see and ump up the speed. Like I said, maybe we'll double the speed up to maybe 12 or 15 kilometers per second. But it's a very good question, but we did not do that for this time just because of our mission objectives for this demonstration mission. Well, you have to, you know, start out with a single data point and then move from there and then- Exactly, exactly. Yep. So Chris has a question. She's, he or she, I'm wondering what would be the expected impact energy? Could you put that in perspective in terms of some of the terrestrial impact events? So the impact energy if dimorphos hit the earth? Is that what you're asking? I think that related to the impact of dart into dart. Oh. Yeah, so keep in mind the objects that we're talking about. So for example, Chelyabinsk was a 20 meter diameter asteroid. And it was roughly 12,000 tons coming in at high speed. It was like 18 kilometers per second. And it released an energy of, you know, 440 kilotons. Okay, so anywhere from 15 to 20 times the explosive yield of the atomic weapons used in World War II, just to give you a sense. Dart is much less, it's like 676 kilograms moving it at 6.6 kilometers per second. So it's still gonna be an impact, but it's not gonna be anything like any of the energy that's been released for some of these bigger asteroids. If anything, it's gonna be akin to some of the very, very smaller asteroids on the small size, like, you know, a three or four meter guy, maybe even smaller than that. So much less energetic than some of these bigger guys, bigger asteroids coming in and hitting the earth. I hope that answers the question. So staying with Chelyabinsk for a minute, we had a couple questions about that. Randall was wondering, was your group aware, I guess was anyone aware of it before it hit our atmosphere? Yeah, so there's a, I'll tell you a funny story. So no one, it caught everybody's surprise, surprise, because we were expecting another asteroid to come through, and it was DA-14, right? So everybody was looking for DA-14, which is gonna make this close approach come up from the south, and everybody was focused on that. And all of a sudden, out of the direction of the sun came Chelyabinsk. And I remember distinctly watching congressional testimony of the Air Force General who's in charge of Space Command at the time, and he was asked the question, the same question is, when were you aware? And his reply was when it exploded over Russia. So, you know, these asteroids have a habit of coming in, they're really hard to detect, and especially if they come from the sunward side, it's almost impossible to detect them until the very last minute. So I was rudely awakened early in the morning by my phone going off, and it was a very interesting day. I've never been so busy in all my life, but that was, it was an interesting time. And again, that's a talk for another session. So I'm happy to give that one all about Chelyabinsk if you guys want. So Gregory Assa, staying with Chelyabinsk, where is the main mass of the 1,400 pounds that were collected now? Is it cut up or still intact as one piece? There might be some meteor collectors in the audience. Yeah, you should, there's lots of pieces of Chelyabinsk around, but the main mass is still relatively intact as far as I understand it. And it's still inside Russia. I think one of the things that happened when they managed to get it out of the lake, they had to use divers and they were held a press conference and they were trying to weigh the mass, measure the mass of it. And it was really difficult because they weren't expecting it, how dense it is. And especially if you're not familiar with the meteorites and how heavy they can be, it was a bit surprising. But as far as I know, the entire mass is still there, but you can still get lots of fragments, right? If you looked at the fireball, there were multiple detonation events. And that was one of the things that was really alarming for people was that when the asteroid hit the atmosphere and detonated, it wasn't a single point, it detonated a number of points across the sky and created that long contrail. And so when you look at it, your frame of reference is okay, that's like a jet or that's like a missile, it's not that far up, but it was really, really big. That contrail was over 200 kilometers long, very high up. And so you're looking at it and trying to get a sense of scale. And then 90 seconds or a bit, then you're hit with a shockwave and it's not just one shockwave, there's a main explosion and then several others, it was bang, bang, bang, bang. And so the people there were really thinking they were under attack. And so that's what made it very scary for them is they had no idea. Fortunately, the Russian military knew right away what was happening once the reports were coming in, they could see as well as the US defense assets as well. So, but an exciting time. Okay, we're gonna go for two more questions and I'm going to apologize in advance for the questions that we're not getting to. Irene wonders if you could address the Friday, the 13th, 2029 asked for the Pofas, whether it will need to be moved, I read early reports that it would hit Earth later that it wouldn't. Yeah, I'll address that one real quick. So good question, the Pofas has been on our minds quite a bit. It's still a really interesting asteroid. There's gonna be a close flyby of it, April 13th, 2029. NASA, we're figuring out what we're gonna actually do in terms of a scientific investigation. Fortunately, it had a relatively close approach and we knocked too long ago and we managed to get some radar data on it. And so radar is really good at determining precise orbit and also physical characteristics of the asteroid if it gets close enough. And in this case, it did. And you can propagate the orbit if you have really good data and propagate it out for a long period of time, even though it may come close to the Earth. And one of the things that the radar data showed us is that a Pofas is not gonna hit us for another 100 plus years. It's not a hazard. So right now, it's not a threat and we don't have to move it. But the fact that it's gonna be coming very close to Earth, it's a fact, it's gonna be third magnitude. So you guys could see it naked eye if you're in Africa and Europe. It's gonna be a really good opportunity for a scientific study. So that's one of the reasons why we're excited about it. So a chance to study a 300 meter-ish size asteroid as it makes a very close approach to Earth. So it's a great opportunity. All right, now our last question from William basically is wondering what can we do to get better at observing and discovering objects coming from the sun's direction? So it's a really, really good question, William. And so that's one of the reasons why we're really looking forward to the NEO surveillance mission going up. So that's the spacecraft that I mentioned launch in about 2026 timeframe. We're hoping it's in development right now. And that would be placed between the Earth and sun at Lagrange point one, and it's a stable orbit. And it's an infrared telescope. And basically what it will do is it will scan the sky. It doesn't look at the sun, but it looks in the direction of the sun. But it covers the approach areas of asteroids from that direction, right? And so it covers our blind spot. So we have our ground-based optical telescopes that will work at nighttime, and they tend to work more at opposition. So looking at the opposite direction of the sun. And now we'll have the NEO surveillance mission that will work in the opposite direction and looking more towards the direction of the sun and cover that blind spot. So we're hoping with that system and then the Vera Rubin telescope coming online, we'll have a lot more information on these type of objects and hopefully find these asteroids before they find us. And that's the goal. If we can find them early enough, then we can prepare and make a natural hazard completely disappear. And that's one of the things that me and my colleagues here at NASA and around the world, we're working very hard to make sure that we don't get hit again and we can prevent this natural disaster from happening. Right. Well, thank you so much for all that you do. And thank you so much for coming and sharing with us. This is really enlightening and really a fascinating technology demonstration mission. And one of the things too, before we close, as we've noted in the past, bringing these webinars to you is truly a team effort. Over the years, Paige Graff, who was one of our panelists this evening, and maybe she'll turn her camera on, from the Aries program at NASA Johnson Space Center, has introduced us to a great many scientists over the years who we have featured in these webinars. Thank you, Paige, for all you have done to help us bring the very best of NASA science to the Night Sky Network. So thank you. And that's all for tonight. Thank you, Paul. Thank you, Paige. Thank you, Dave and Vivian. And thank you all of you for tuning in. And you can join us for our next webinar on Thursday, October 28th, when Dr. Robert Zellum will share with us what we currently know about exoplanets. And we're gonna go from the ones that are really new near Earth to the most distant planets up around other stars and how all of us can get involved as citizen scientists. Also join us on Saturday, October 9th, as Dave noted earlier, for an International Observe the Moon Night Kickoff Party. You can find an archive of these webinars on the Night Sky Network website in the Outreach Resources section and on the NSN YouTube channel. So keep looking up and we will see you all next month in just a couple of weeks, actually. So good night, everyone, and good morning.