Quote (Matao @ Dec 21 2011 02:02pm)
thats not true at all
what we do know , is that as soon as earth settled down enough for life to form , it appeared on earth
and that life is abundant in , on , and above the earth
and there is not a single reason to believe that it hasnt appeared elsewhere
I agree with you that it probably has, but there's no way we can say that we
know it has without actually getting evidence to support that fact. For example, if we find bacterial life on Mars when we go back (because we will, inevitably, go back on a manned mission -- even if it's not NASA that does it) then we will
know that life happens and that it's not as rare as we currently think it is.