Learning more about where the water is today and where it was in the past will also guide future studies about whether Mars ever supported life.

It's great these images turned out well because a lot of things had to work right, including exactly how the spacecraft points and the stability. It turned out just right.

They're great images. They're what all of us were hoping for - better than some people were expecting.

At this point we have an idea that water is probably abundant on Mars in the form of ice. It's not a matter of finding water on Mars but learning its importance in climate change ... and clearly it has been important to shaping the landscape.

While a little bit of heat is produced by radioactive decay, this is a very small world and that (heating) is pretty minor.

It isn't understood how that is happening.