The rocks, to a great extent, look swept clean. It's a much cleaner surface than what we had a right to hope for.

Is there water still on Mars? I don't have a view on that because we don't have good data to answer that question. One of the biggest mistakes you can make if you're a scientist is to think you know the answer, or wish for a certain answer, before you actually have it.

We didn't know if the rover could climb up or down the hills of the crater.

These rovers are living on borrowed time. We're so past warranty on them. You try to push them hard every day because we're living day to day.

We have concluded that the rocks here were once soaked in liquid water. It changed their texture, and it changed their chemistry. We've been able to read the tell-tale clues the water left behind, giving us confidence in that conclusion.

I can't ever remember not wanting to be a scientist.

My style of leadership is to lead with the lightest touch that I possibly can.