Why is it more likely that life existed on Mars billions of years ago rather than now?
Mars was once a much wetter place than it is now and at some point it had liquid water flowing on the surface, some massive disaster happened on Mars that made conditions what they are today, some people think Mars even had a thriving ecosystem as diverse as those in the rain forests of Brazil, but odds are that Mars was more of a primordial world where life was just beginning to start, most of the life was probably based in the seas and oceans, however nobody can be 100% sure this is the case until some kind of fossil record is made, and that means humans need to go there themselves so we won’t find out anytime soon.
