Spirit Sol 488

"Good, but not perfect." That's Chris's assessment of yestersol's drive. The first guarded arc, meant to take us safely down a smooth slide to our final position, refused to move. This later turns out to be a combination of dangers from nearby hazards -- a couple of rocks beside the top of the slide that are near, or barely above, the hazard-avoidance code's safety threshold -- and an unknown patch on the slide itself, a result of the slide being too smooth for the stereo correlator to determine distance.

So we're about 7m away from our goal. It should be an easy drive thisol, and luckily I prepped the science team in advance, warning them that it might take us three sols to get there. I'm learning.

Today I find out why the science team is so eager to return to Larry's Lookout. From this side, they can see that it's volcanic rock that was altered by water. Not only is water what we came to find, but this alteration is specifically interesting because this rock is tens of meters above the surrounding terrain. That means the water here at Gusev Crater wasn't shallow, and probably wasn't just embedded in a light but long-term sulfuric acid mist (one of the theories I've heard before). This stuff was deep -- tens of meters deep at least. This could be the evidence we were hoping for all along, the evidence of an actual lake here at Gusev.

Tomorrow we should be at the base of the lookout, maybe another sol to climb to the rocks. Then we'll know.

[Next post: sol 494, May 24.]

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Courtesy NASA/JPL-Caltech. The view out our front windshield as we planned thisol ....


Courtesy NASA/JPL-Caltech. ... and the corresponding view out the back.