3 ms·

Space is pretty inhospitable though. Is it possible for living organisms to survive ejection, a space journey and re-entry?

rootbear 8y ago
It's an open question, but there is some reason to believe that bacteria can survive a journey through space. Multicellular life would be much less likely to survive, although I'm constantly amazed at how hard it is to kill a tardigrade!
- mda 8y ago
  Long journey to Mars in hard vacuum and under UV radiation makes it very unlikely, but bacteria spores are very resilient to harsh conditions. I think it is still theoretically possible. There are a few papers on this. https://www.ncbi.nlm.nih.gov/m/pubmed/11539977/ https://www.ncbi.nlm.nih.gov/m/pubmed/11539977/
- sureste 8y ago
  It's called panspermia, for the curious.
- dustfinger 8y ago
  A tardigrade must first complete cryptobiosis, otherwise they are fragile[1]. Given that it takes time to enter cryptobiosis (maybe 1 hour), it is unlikely that any active tardigrade would survive a meteor impact. Suppose a tardigrade was in complete cryptobiosis and survived a journey to the surface of Mars. Conditions would need to be favorable if it were to ever regain an active metabolic state. [1]https://www.quora.com/What-does-it-take-to-kill-a-waterbear-tardigrade https://www.quora.com/What-does-it-take-to-kill-a-waterbear-...
reallydude 8y ago
> Space is pretty inhospitable Is it? Predation, old age (wear and tear), disease (pollution) are the primary reasons that what we consider "living things" die. Space has very limited vectors of death for something like the tardigrade. To some bug dessicated hibernating in a rock, it's not too bad.
- stcredzero 8y ago
  Eventually, cosmic ray damage will even get the tardigrade.
- wk_end 8y ago
  > Predation, old age (wear and tear), disease (pollution) are the primary reasons that what we consider "living things" die. ...on Earth, where the multitude of things that make space inhospitable - both objectively, like no atmosphere to protect from cosmic radiation; and subjectively, like vastly different conditions that terrestrial life hasn't evolved for - aren't an issue.

rootbear 8y ago

It's an open question, but there is some reason to believe that bacteria can survive a journey through space. Multicellular life would be much less likely to survive, although I'm constantly amazed at how hard it is to kill a tardigrade!

mda 8y ago
Long journey to Mars in hard vacuum and under UV radiation makes it very unlikely, but bacteria spores are very resilient to harsh conditions. I think it is still theoretically possible. There are a few papers on this. https://www.ncbi.nlm.nih.gov/m/pubmed/11539977/ https://www.ncbi.nlm.nih.gov/m/pubmed/11539977/
sureste 8y ago
It's called panspermia, for the curious.
dustfinger 8y ago
A tardigrade must first complete cryptobiosis, otherwise they are fragile[1]. Given that it takes time to enter cryptobiosis (maybe 1 hour), it is unlikely that any active tardigrade would survive a meteor impact. Suppose a tardigrade was in complete cryptobiosis and survived a journey to the surface of Mars. Conditions would need to be favorable if it were to ever regain an active metabolic state. [1]https://www.quora.com/What-does-it-take-to-kill-a-waterbear-tardigrade https://www.quora.com/What-does-it-take-to-kill-a-waterbear-...

reallydude 8y ago

> Space is pretty inhospitable Is it? Predation, old age (wear and tear), disease (pollution) are the primary reasons that what we consider "living things" die. Space has very limited vectors of death for something like the tardigrade. To some bug dessicated hibernating in a rock, it's not too bad.

stcredzero 8y ago
Eventually, cosmic ray damage will even get the tardigrade.
wk_end 8y ago
> Predation, old age (wear and tear), disease (pollution) are the primary reasons that what we consider "living things" die. ...on Earth, where the multitude of things that make space inhospitable - both objectively, like no atmosphere to protect from cosmic radiation; and subjectively, like vastly different conditions that terrestrial life hasn't evolved for - aren't an issue.