[TexasFreeper2009]

um... I think any lichen attached to anything would burn up entering the atmosphere.

And plus this silly explanation doesn't explain the origin of life... it's just a cop out by saying it must have started elsewhere.

[onedoug]

I supect the panels would have been re-stored in the returning spacecraft.

[rottndog]

That’s the very first thought I had...even if some microscopic life form made it to Earth, how could it possibly survive the inferno of getting through the atmosphere?