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Well, calling Allan Hills 84001 "unsterilized" is a bit of a stretch, since even the most optimistic theory is that it contains fossilized lifeforms, not live o
by mrec 11y ago
Well, calling Allan Hills 84001 "unsterilized" is a bit of a stretch, since even the most optimistic theory is that it contains fossilized lifeforms, not live ones.
I dunno. I agree that something like the K/T impactor probably blasted bits of our planet all over the Solar System, but I suspect the depth of the gravity well brings more factors into play than just "how long it would take for ejecta to get to X". For example, accelerating a bit of surface to escape velocity would involve a lot more energy on Earth than on Mars, and at the point of impact I'd have thought that energy would translate to possibly-sterilizing heat.
- Symmetry 11y agoThe hypothesis, I believe, is that the stuff in Allan Hills 84001 was fossilized back when Mars was wet but it was only ejected a few million years ago. The important part is that the inside of the rock never got too hot. As long as there are bacteria which can take being frozen for long periods of time they ought to be able to survive. As to larger impacts I really can't speak with any authority and I'm not aware of any studies which would say. But my intuition would be that the greater volumes in large the ejecta from large impacts would heat up less due to more insulation. I should probably put this on /r/askScience and see if anybody knows more.
- Retric 11y agoLarge asteroids are generally frozen on the inside when they impact the earth, similarly any large ejecta would likely contain pockets that remain relatively cool. Polar ice would actually be a great candidate for such a transit.