Post Block Island Meteor Studies (The Western Route), The 6th Leg in our Zig Zag Journey to Endeavour Crater Options

[ustrax]

Marquette abstracts are out:
http://www.lpi.usra.edu/meetings/lpsc2010/pdf/2109.pdf

[fredk]

More patches than strips... The only problem may be getting a good spectrometer reading. But the brushed surface alone looks so clean... that I wonder if the reading would be much different a couple millimeters down anyway.

Interesting comments about the Marquette grind in the latest planetary society report. Squyres says that even though the brushed surface looks clean, the composition is actually very different inside. So that made it hard to get good readings:

“We would have liked to blast right into it, making a 5,6,7-millmeter grind to put a deep RAT hole where you would blow any weathering layer across the entire RAT hole and put on the APXS and get one good measurement. The problem is we don't know how much grind capability we’ve got left and we think it's not much. Moreover, it turned out we were correct that Marquette Island is an extremely hard rock and a good hard grind could have taken the instrument out completely.”

But they were able to compensate:

the rover would take several different measurements at different parts of the RAT hole. “You assume you're seeing a mixture of surface and subsurface material in different proportions depending on where you're measuring. So, by taking multiple measurements and connecting a line between them you can both interpolate and extrapolate and learn quite a bit about what the composition of the individual end members are, especially since we know what the surface material looks like already,” Squyres explained. “We did that and are in the process of doing the calculations.”