Steven Squyres

A professor of astronomy at Cornell, Squyres is the principal investigator for the Mars Exploration Rover mission, which landed two robotic explorers, Spirit and Opportunity, on the planet in January 2004. As of mid-December both were still operational. He spoke with Jerry Adler.

Well, we didn't expect this year even to happen, so every year now is a good one.

The design lifetime was 90 days, and we're coming up on three years. Spirit spent most of the year exploring a feature we call Home Plate, an explosive volcanic deposit with interesting geology.

Because it's shaped like one. The news from Opportunity is that it arrived at Victoria Crater, which is nearly a half-mile across, and the deepest window into the subsurface of Mars we'll get.

We traveled around 4.6 miles in 637 Martian days, which are a little longer than Earth days.

I think we've found a safe way in. I don't know if we have a way out yet.