[X] My Assistant

[Zelenyikot]

Little veins in Shaler on Sol 322

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[SFJCody]

http://astrogeology.usgs.gov/news?id=news/...nhoff-road-trip

We have started the long traverse to the base of Mt. Sharp (Aeolis Mons), the long-term goal of the mission! It may take a year to get there, depending on how many interesting features we find along the way. The challenge for the science team will be to identify the most important targets along the way, and to study them without delaying drive progress too much. Today we are planning targeted observations, followed by another drive over the weekend.

Here we go then! Mountain bound! Looks like a new thread may be in order, too.

[dvandorn]

In re the dark dunes, they remind me of El Dorado in Gusev. That dark dune field, while much smaller than the ones ringing Mt. Sharp, looked as dark from a distance and from above as the ones here in Gale. When we got really close to El Dorado, we found there is a thin layer of the ubiquitous red dust on the mini-dune ridges, but it's mostly just black basaltic dust.

I would imagine these dark dunes in Gale formed by a similar process as that which created El Dorado, an area that is wind-shadowed in such a way that the black basaltic grains are preferentially dropped from the general airborne dust entrainment. Or, maybe not exactly a wind shadow, more of a place where Mt. Sharp's effect on the winds causes the exact right kind of instability in the air that causes the preferential deposition.

The big difference between these extensive dune fields here at Gale and the El Dorado field in Gusev is that Mt. Sharp is a much bigger hill than Husband Hill was, so these dune fields are much larger and seem to show some differences in albedo (we'll know about textural differences when we get there), depending on how far away from Mt. Sharp you are (or maybe the angle of repose upon which the dunes formed; the two are sort of interrelated). Could be that the "edges" of the wind instability that causes the preferential deposition show a more well-mixed deposition? Again, something we will know more about when we get there.

In any event, we see this effect literally everywhere on Mars, be it influenced by mountains, crater rims or whatever causes the right kind of instability that causes the preferential deposition. It's certainly not unique to Gale.

-the other Doug