Wednesday, December 21, 2005

Big Push

Sorry I dropped off for a couple of weeks - I got busy with a couple of real things. I wrapped up a paper and an LPSC abstract based on the work I did for my MER team proposal. The science that I'm interested in relates to large impact events, what they do to rocks, and what information we can pull out from the rocks about the impacts that created them. So far in my career, I've been able to get some interesting impact information from terrestrial rocks, lunar rocks and from meteorites - but all by picking up the rock and taking it into the lab for analysis. Mars is a whole different story. These rovers are strictly in-situ instruments. They can't pick up rocks and turn them over. They can't break open the rocks to look inside. And they certainly can't launch the rocks back to Earth for me to be able to put them in the lab! So it's required a change of reference frame for me.

The first thing I did was to try to determine how much material at the MER landing sites might have been thrown there by large impact events - no sense trying to look for things that don't exist! Using some simple equations, I estimated that at least at the Spirit landing site, we should expect to see a couple of horizons of interesting impact ejecta. So I worked up that first attempt into a paper and an abstract that I'm sure will generate some discussion at our next meeting in March. But, this isn't a straightforward exercise. Though we understand quite a bit about lunar and terrestrial craters, Mars is more complicated in a lot of ways. Mars probably has water ice in much of its subsurface and when a meteorite slams into the rock + ice mixture, strange things happen. So now I have to take the next step and try to understand more about Martian crater forms.

Now that I have more access to data and more importantly, to knowledgeable scientists, I'm also diving into trying to identify the rocks that might be products of impacts and to be able to get information out of them. That's my 2-year plan, though, so that's a big mountain of learning ahead of me. :)

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