"Earth's oldest fossils have been found in Australia by a team from the University of Western Australia and Oxford University. The microscopic fossils show convincing evidence for cells and bacteria living in an oxygen-free world over 3.4 billion years ago.

 

The team, led by Dr David Wacey of the University of Western Australia and including Professor Martin Brasier of Oxford University, report the finding in the journal Nature Geoscience.

 

'At last we have good solid evidence for life over 3.4 billion years ago. It confirms there were bacteria at this time, living without oxygen,' says Professor Brasier of the Department of Earth Sciences at Oxford."

 

http://www.sciencedaily.com/releases/2011/08/110821205241.htm

there are possibilities sincesome scientist thinks there are water in mars and that it’s soil constructionwas not far from the earth made of, it is indeed feasible some life(e.g.microorganism) was roaming there.

 

 

Interesting, but not in my view as radical as the press coverage implies. Most workers in the field have thought for some time that there was good evidence for life in the 3.4 to 3.5 Ga range. This 2007 review paper concludes "Taken together these data show why it is that most workers in the field of Precambrian palaeobiology are of the view that the “true consensus for life’s existence” dates from >/= 3500 Ma. "