Also, we're doing what any field geologist would do in an area like this: climbing to a good vantage point for plotting a route.

But that's purely conjecture at this point … a working hypothesis. Everything is on the table until we've gotten more data down.

Wind has to be involved at some level you figure. Frost might have helped. A frost build-up on arrays could coagulate the dust...but the fact is that we don't understand it very well. But I'll take it.

[Before launch] it just seemed impossibly far away, it seemed unreachable. Tonight, I go out knowing our rovers have been there a whole Martian year...it's a much more familiar planet. We know the place.

There are cliffs the rover could fall over and die if we aren't careful. We are gong to proceed carefully and methodically.

That's no Mt. Everest, but it's a heck of a climb for our little rover, ... When we first touched down at Gusev Crater on Jan. 4, 2004, the Columbia Hills looked impossibly far away.