Scientists in China say they have discovered that a type of moss would survive on Mars.
Syntrichia caninervis is type of moss usually found in regions such an Antartica or the Mojave desert.
But now, scientists has been found that it can survive Mars-like-conditions including drought, high levels of radiation and extreme cold.
You are probably right, but how cool would it be if we are wrong.
Also, any evidence of life that may have been existed on Mars previously would be erased.
I assume you have read the Kim Stanley Robinson trilogy. When I read it, as a teenager, I was definitely a Green-Mars proponent, but as I grew up learnt more about palaeontology and geology, I became more of a Red-Mars proponent.