The three bottlenecks: ejection, space travel, reentry

13:24mechanical challenge of planetary escape and then getting to Earth. Mhm. >> Okay? So, there's three bottlenecks when it comes to panspermia. Three things that prevent it from be like being realistic happening. >> Yeah. Yeah, exactly. There's The first one is the impact ejection event, right? You get an initial shock, an asteroid impacts you. That's going to cause a bunch of pressure over microseconds and it's going to eject stuff into space. You got to survive that impact. >> Mhm. Okay. Once you survive the impact, then you got a journey through space, millions of years in a vacuum, there's cosmic radiation, there's extreme cold,

14:05there's UV, right? And then at the end of the day, after you've done that journey, you've got to survive re-entry. Mhm. Okay? Mhm. So, You have to be big and bulky to survive impact, you have to have endurance to last a long time, and and and you maybe more also endurance and being big to survive re-entry. >> Exactly, right. So, the two and three, which is surviving space and then surviving re-entry, that's actually been a explained by something called expose, which is a facility on the International Space Station. What they did was they had certain organisms and spores that they put out into the deep space, right

14:48outside the International Space Station, and it turns out these things can survive prolonged space exposure. >> Mhm. If they're shielded by a few millimeters of rock. Interesting. >> So, if your life is just a few millimeters millimeters the surface, yeah. Underneath the surface of whatever asteroid, it's going to survive not only the vacuum of space, but also the re-entry into Earth. That's actually quite I I I think if people were to try to guess, if you have a a piece of rock floating through space with the little little thingies, little micro thingies on it, Uh how deep do you think it needs to be to be able to survive? I think very few people would have said

15:28guessed millimeters. >> Guessed millimeters. >> You would think you need a little shielding, you need a little maybe a couple inches, maybe a couple feet, yards. >> you don't need a lot. That's actually really cool. The interior of the rock actually heats minimally when you go into atmospheric entry. >> Oh, yeah. Okay. That's that that's the idea, right? And they actually found that this particular bacterium, D. radiodurans, Mhm. it was already It's like survived space-like conditions and it's the best at it. Oh, okay. Okay. >> so, this particular paper that's coming out of Johns Hopkins, it is targeting bottleneck one, which is the idea of can it survive the initial ejection event? Cuz we already know it can survive outer space and re-entry. We need to know if

16:09it survives the ejection. >> So, it can survive two and three of the three bottlenecks. We have ev- we have uh uh uh data, experimental data, that shows that to be true. It's not It's not theoretical. >> Yeah. But number one is still Number one is still yeah. Like it's like it's like if there's life on Mars and I hit it with an asteroid, by the time it gets out into outer