[X] My Assistant

[MizarKey]

Check this stereo view out taken with the nav cam on Sol412...looks like Oppy passed right by an interesting rock. I've looked to see if there's any other images of it but couldn't find any. If any of you find it, let me know...thanks.

[alan]

Is there a mixture of light and dark sand in this image?
http://qt.exploratorium.edu/mars/opportuni...00P2956M2M1.JPG

[dvandorn]

Is there a mixture of light and dark sand in this image?
http://qt.exploratorium.edu/mars/opportuni...00P2956M2M1.JPG

Hey, yeah! The sand in the sun is a *lot* lighter than the sand in the shade...

Seriously, yes, I think there are some noticeably lighter grains in the sand here. Looking at the high-res orbital imagery, we should expect to see an increasing population of lighter-toned sand, preferentially distributed along what appear to be the leeward sides and bases of dune formations. A lot of the "etched" terrain detail appears to be made up of lighter-colored soils displayed preferentially along leeward dune sides as you get close to stretches of true evaporite outcrop. (Whether the lighter dust is displayed via depositional or excavative processes is hard to say, of course.)

I would think that the regolith in the area we're approaching (that looks considerably lighter in the orbital imagery) is of different composition than what we've seen thus far. Maybe it contains more evaporite erosion products than the soils on the flatter plains to the north? And a smaller proportion of concretions and concretion erosion products? That could point to either different erosion patterns (because of the relief from the large, old degraded crater cluster that includes Albert) or a change in concretion production from north to south.

Either way, it's just *fantastic* that Oppy is capable of driving several kilometers from its landing site in order to characterize such differences over distance. Brings tears to my eyes, I'm smiling so hard...

-the other Doug