Re: And on Earth 3.5 billion years ago?
Even if only simple life was present (bacteria style, nothing as complex as fish like creatures), if Mars had something akin to stromatolite producing bacteria of Earth then may* be possible to detect signs of life.
Stromatolite rock formations can get large compared to bacteria that created them (a metre in size has been seen on Earth).
*Problem is, can be very tricky to know a bit of rock is a bacteria produced stromatolite, as plenty of inorganic process can produce similar rock formations.. and problem becomes much worse if your "candidate" piece of rock is stuck on Mars
Biting the hand that feeds IT
