Mars is the coolest planet for lots of reasons. (-50C)
One of the reasons I am so interested in it is that humans can survive on mars with the technology we have now.
Potentially Mars may have had life and maybe Europa or Ganymeade (Jupiters moons)...there is a neat little band called the goldielocks band. (look children's books get a look in) When scientists search for life in other solar systems...too hot.. too cold... just right..earth, mars, and maybe just maybe the moons of jupiter fall into the just right band...
Phoenix has landed in the Martian arctic. It is drilling for liquid water.