If we find evidence that (those) minerals are there, there must have been a time in Mars' early history when there was standing water on Mars' surface.

The instruments that are arriving (in 2003) have influenced our selections. We're trying to complement, not duplicate them.

With the subsurface of Mars, we've literally just scratched the surface and we're trying to probe, now, more than a couple of feet into it.

We're especially interested in water, whether it's ice, liquid or vapor. 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.

These are some of the highest regions of the planet because they sit on top of southern hemisphere terrain, which is higher than corresponding terrain in the north.

Every time we look closer, we see surprising new things.

There are many unanswered questions about Mars.

I'm sure the U.S. would like to have a presence there.

Every time we look with increased resolution, Mars has said, 'Here's something you didn't expect. You don't understand me yet.' We're sure to find surprises.