Mars once had water. Lots and lots of water.
That does not mean that evidence of life has been found — but it suggests that life could have evolved on Mars just as it did on Earth, NASA said.
It does mean NASA can go ahead with a plan to eventually send people to Mars.
Two questions:
1. What are the odds of life evolving on two planets in one solar system?
2. What difference to future missions does finding water make?
Not So Fast 