There's no question there's other life on planets out there, it's just doesn't have to be sentient, like some people seem to think all life is... Anyways, if I remember correctly, there's algae frozen in the ice caps of Mars.
And just for the heck of it, research "water bear". Evolution entails adaptation, but these little critters have done way more that just that. Water bears can go into a hundred-year hibernation. In that hibernation, they can surive radiation that'd kill any other animal. They can survive without any atmospheric pressure. They can survive without anything to sustain them. In other words, they can space travel. Scientists have studied them for a long time, and have tested them in space-conditions, and they survive.