 Two intrepid travelers jump randomly from star to star in a ship that tunnels through folds in space. Their quest? A new world. One that could be a second home for a zone. But when the space weather forecast is sunny mixed with intermittent sizzle, one should think twice about moving into a new home. Even when it's found in a place astronomers call the habitable zone. Jump complete, beginning standard system scans. What kind of system did we jump into this time? I'm not sure yet, but wow. Have you ever seen so much stellar activity? Those prominences are huge. But isn't that star pretty small? These measurements indicate it's an M6 red dwarf. Only about 50% bigger than Jupiter. It's funny. What is? I always figured that a red dwarf star would be red. That looks orange. Hang on. It looks like even the coolest star is a lot hotter than things that normally glow red, like lava. Honestly, it's brighter in the infrared. Wouldn't it make more sense to call it an infrared dwarf? Totally. But whatever we're going to call it, the planet's going to have to orbit pretty close to such a cool star to be warm enough for liquid water. You ready to bring us into the habitable zone? The telescopes can find any earth-sized planets around here. I said I'm working. I'm looking here. Like those? I'm trying. Well, what do you know? Planets. Everything here is all bunched up around that star. There's a large planet right next to it over there, a couple more further out. And one right smack in the middle of the habitable zone. Hang on then. Take it as in. So if this one turns out to be nice and cozy, what do you want to do when we get there? We set down somewhere nice and warm. Relax, maybe take a little swim, get it infrared suntan. That's a thing, right? Sure. Why not? Okay, prep for deceleration. Check. From our orbital data, the planet's stars are looking pretty good. About 90% the size of Earth, 70% of its mass. So that means that it's gonna... That means things will be 15% lighter there. But it likely won't matter how strong the gravity is. These atmospheric readings are no good. What's wrong with the atmosphere? There's not much of it. Surface pressure is only around 8% of Earth's standard at sea level. Computer Brad, you're the closest thing we have to a doctor on this ship. How much air pressure do humans need to survive? Human blood will start to internally boil at air pressures below 6% of Earth's sea level standard. So it's barely survivable? However, even when breathing pure oxygen, the ambient pressure must be at least 12% of sea level to maintain minimum survivable blood oxygenation levels. Or not. Okay, that's enough bad news out of you, computer. That is one desolate world. Do you see all those dried up ocean beds? If there used to be oceans, what happened to them? Whoa, is it my imagination or is it getting a lot brighter out there? Oh, that looks like the mother of all stellar flares. It's already doubled the brightness of the star. And aside from all that ultraviolet and X-ray light, I expect a nasty blast of ejected particles will reach us just under an hour. That might be even better than the infrared sun tan you were hoping for. Flash tan from all that UV topped with a little hard radiation sizzle. No, I'll take a hard pass on that. You know, this might explain what happened to the planet. All that irradiation could have been hostile to the formation of life. Yep, and the repeated bombardment from stellar flares could have over billions of years eroded the atmosphere away. Similar to how Mars lost its atmosphere long ago. Oh yeah, I know a lot about Mars. As it lost atmosphere and the pressure kept dropping, the oceans would have started evaporating at lower and lower temperatures. And I'm leaving this rock behind. Everything was perfect here for making a habitable planet, except for that. But we've known M dwarf stars can be very active, like the sun's neighbor, Proxima Centauri. Are you done taking your readings? Or do you want to hang out and see if our shieldy can handle everything that's hanging our way? Oh, let's go. Here's hoping the next star we visit won't be so aggressive. Location, location, location is the realtor's mantra. Universal advice for those looking to buy a new home. But it implies equally well when searching for a hospitable world. No amount of fresh air and temperate ocean will in the long run make up for a star that scours the planet with flashes of ultraviolet and X-ray radiation and blasts of stellar particles. As our intrepid explorers have learned, these effects can render the most pleasant world barren, even if its location is in the habitable zone.