Opportunity Sol 562 (Spirit Sol 583)

Ladies and gentlemen, Spirit has arrived.

More or less.

The science team certainly seems to think so, and sent out congratulatory email to that effect. And Chris Leger has an argument that we're there: "Spirit's NAVCAMs can see horizon in every direction. If you were standing there, you'd say you were on the summit."

But the rear HAZCAM tells a different story. There's still a slight rise behind us, which peaks just a little way out -- less than ten meters, to my eye, probably more like five.

So we're there. Or we're not, depending on how you look at it. And maybe this isn't such a bad outcome, in its way: it gives us something to argue about, and more people who can plausibly claim to have been involved. I know I'm happy.

But I'm not on that rover; I'm back upstairs in the Land of Opportunity. I've been gone only a couple of weeks, but it feels a lot longer. Opportunity has spent almost the entire time IDDing outcrop, mixing in a couple of short bumps to sample additional tasty regions. But thisol it's time for us to move on, and we're striking out boldly. The whole drive doesn't cover that much distance, only 25m or so, but it's a long, winding one, a very rough "S" that wanders south and then north and then flattens out, hopping three ripples in the process. The point of all this meandering is to take us east toward Erebus Highway, which the scientists have decided, based on the outcrop we've just seen, that they definitely want a look at. (Cooper points out that this eastward jog will more or less maintain our radial distance from Erebus Crater, thus preserving the property that Erebus is always two weeks away. My theory holds!)

I can't refrain from asking the scientists what's so interesting about
the outcrop here. "Are you just starved, or does it taste good?" I ask Larry Soderblom, who at the moment is just a voice on the telecon. "I mean, are you guys just excited to see rock again, or is there actually something scientifically interesting about this rock?"

"Some of each," he laughs. "This outcrop is different from all the previous outcrop we've seen -- all of that stuff was exposed by impact events and maybe affected by them, so now we get to see the differences between that and non-impact-affected outcrop. Also we can check out the lateral variations in chemistry." Meaning, we get to see whether the water in this area was doing the same stuff as the water where we were before.

"Are you seeing any differences?"

I can hear the shrug. "We haven't seen enough of this stuff to tell. That's one of the reasons we want to get to the Erebus Highway."

"We're also gaining elevation as we head south," I muse. "Are we ever going to reach the shore of this sea? Maybe find areas that weren't affected by water after all?"

"Don't know," he admits. "There's a debate about whether we're going up or down in the stratigraphic sequence." I guess that should have occurred to me: just because this area is higher now, doesn't mean it was higher when the water was here. That sort of thing can happen to planets. Oh, well; that's why Larry's a geologist and I'm just a lowly Mars rover driver.

A lowly Mars rover driver who took Spirit to the summit of Husband Hill.

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