Hi all, If we find some fossils there, will we be able to tell if it's DNA-based? Similarly if we find fossils (or even current life) on Europa what is it likely to be based on? I'm very curious if extraterrestrial life is like what we have here on earth or not. It seems clear that whatever life we find we will be related to it in some way. But I would like to find some theories on how long we have to go back to find a "common ancestor". Will it be a supernova explosion that spread the chemical elements throughout our region of space, and then life evolved based on different elements? Or has life evolved in similar ways but independently on different planets. (like for example the evolution of the eye on earth)? I realize we don't have answers to all these questions (and that I'm probably not phrasing the questions in the normal scientific way), but I would like to know what the leading researchers think. Do you guys know where I can read more about these things?