The thing that sets Mars apart is that it is the one planet that is enough like Earth that you can imagine life possibly once having taken hold there.

The thing that sets Mars apart is that it is the one planet that is enough like Earth that you can imagine life possibly once having taken hold there.

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.

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.

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

There's no way to actually turn the rover off.

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