Biology Stack Exchange is a question and answer site for biology researchers, academics, and students. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

It is possible that life has invaded mars or the moon by way of probes rovers and other man made tech. How many years or generations of sequential and phenotypical diverge would be necessary to establish the organism as astrobiology?

share|improve this question
Are you asking how long an organism must live in a non-earth environment before it is considered astrobiological? – yummyclaypot Jul 21 '14 at 19:02
Yes i am @nbogard – user1357 Jul 21 '14 at 22:13
Well, it is just a matter of definition. You can make up your own choice! – Remi.b Jul 22 '14 at 17:56

I think if life was transferred to either body on a probe, it would not count as alien yet because it could not have had time to develop very far on its own, since all probes are recent evolution wise. These would be offshoots from earth life. Truly alien life would most likely use different biochemistry because it originated in a different planet, it would be a totally different tree of life. However, the presence of life on the moon or mars, even if just contaminating earth bacteria, would be incredibly important for astrobiologists, as it would provide direct evidence that life can survive in these harsh environments. Life on the moon would most likely be dormant bacteria, because there is no air or water or food. However, if bacteria could survive prolonged exposure to space and be revived upon entering a suitable environment, that would provide evidence for panspermia. Read this:

If panspermia is true, then those aliens might not be that unrelated after all. But until we find one, we can't make any conclusions.

share|improve this answer
Awh I learned a new word panspermia thank you – user1357 Jul 28 '14 at 23:55

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.