3 ms·

We would never find out if life developed outside of earth.

by chpatrick 6y ago

fny 6y ago
And Jack and Jill won't contaminate space when they're sent to start Earth 2?
- ben_w 6y ago
  By the time we’re ready to even try that, we should have already answered the question, at least as far as whichever target you’re trying to colonise is concerned. (And if you meant space itself, rather than the objects within, could reasonably be described as ‘contaminated’, then panspermia is both very likely how life got started on Earth and a reason to expect it everywhere else too).
njarboe 6y ago
Mars and Earth send surface rocks to each other via meteor impacts that would almost certainly contain live bacteria spores. Life could have started out on Earth or Mars or both, but finding life on Mars won't answer your question on its own. There are even theories that life on Earth was seeding from life from other solar systems, but that is much more unlikely and an in solar system transfer. Check out scholar.google.com and search for "exchange of bacteria between mars and earth" or other similar phrases.
- idiotsecant 6y ago
  I feel like the assertation that meteor impact ejecta would 'almost certainly' contain live bacteria spores and the implication that those spores would survive vacuum , radiation, heat cycling, and dessication for the very long trip from earth to mars is going to need a big old citation required here. That seems like a stretch.
  - njarboe 6y ago
    Here is a very nice and through paper on the subject: "Natural Transfer of Viable Microbes in Space" https://doi.org/10.1006/icar.1999.6317 https://doi.org/10.1006/icar.1999.6317 In the abstract: "The conclusion is that if microbes existed or exist on Mars, viable transfer to Earth is not only possible but also highly probable, due to microbes’ impressive resistance to the dangers of space transfer and to the dense traffic of billions of martian meteorites which have fallen on Earth since the dawn of our planetary system. Earth-to-Mars transfer is also possible but at a much lower frequency."

We would never find out if life developed outside of earth.

fny 6y ago

And Jack and Jill won't contaminate space when they're sent to start Earth 2?

ben_w 6y ago
By the time we’re ready to even try that, we should have already answered the question, at least as far as whichever target you’re trying to colonise is concerned. (And if you meant space itself, rather than the objects within, could reasonably be described as ‘contaminated’, then panspermia is both very likely how life got started on Earth and a reason to expect it everywhere else too).

njarboe 6y ago

Mars and Earth send surface rocks to each other via meteor impacts that would almost certainly contain live bacteria spores. Life could have started out on Earth or Mars or both, but finding life on Mars won't answer your question on its own. There are even theories that life on Earth was seeding from life from other solar systems, but that is much more unlikely and an in solar system transfer. Check out scholar.google.com and search for "exchange of bacteria between mars and earth" or other similar phrases.

idiotsecant 6y ago
I feel like the assertation that meteor impact ejecta would 'almost certainly' contain live bacteria spores and the implication that those spores would survive vacuum , radiation, heat cycling, and dessication for the very long trip from earth to mars is going to need a big old citation required here. That seems like a stretch.
- njarboe 6y ago
  Here is a very nice and through paper on the subject: "Natural Transfer of Viable Microbes in Space" https://doi.org/10.1006/icar.1999.6317 https://doi.org/10.1006/icar.1999.6317 In the abstract: "The conclusion is that if microbes existed or exist on Mars, viable transfer to Earth is not only possible but also highly probable, due to microbes’ impressive resistance to the dangers of space transfer and to the dense traffic of billions of martian meteorites which have fallen on Earth since the dawn of our planetary system. Earth-to-Mars transfer is also possible but at a much lower frequency."