[Cross-posted, edited from Kentucky Space] Sure, water ice and liquid water may have been confirmed on the surface of Mars. And microbial life has been resurrected from a million and a half year glacier nap on Earth. But given the distance from its parent star and the presence of an ethane oceans and methane rain and clouds, Titan's unique hydrology might be the best place to find a brand new kind of life. Technology Review:
We know that life has arisen once in the solar system, but unfortunately this tells us nothing about its ubiquity elsewhere. Life on Earth may be a one-off.
But were we to find evidence that life had independently arisen twice in the solar system, it would provide strong evidence that the universe is teeming with ET creepy crawlies. The key word here is "independently."
Key question: Given our complete lack of understanding of such life, would we know it if we encountered it?