Tuesday, May 02, 2006

Martian winter work, terrestrial summer work

Spirit is nestled snugly in her Winter Haven and we are all getting in on the chance to conduct experiments that we never seem to have time for when we are on the move. Spirit is parked on the slope of Low Ridge, an arcuate feature that might be connected to, and possibly related to, Home Plate. Directly in front of the rover is an expanse of drifted dust and/or soil, which is the first target of an intense campaign with all the arm instruments to make measurements progressively deeper into the soil. There's also a long list of rock and soil targets for miniTES, some long-timeline atmospheric observations, and a monster panorama of our surroundings in all 13 Pancam filters, which should be really beautiful. For those of us interested in rocks, we have poor choices right now. There are a couple of clasts and possibly a shingle in our workvolume, which we will investigate. Several of us are hoping that after the solstice, we will be able to move to some rock targets ahead of us to figure out the geology of Low Ridge, its relationship to Home Plate, and the origin of some of these volcanic units around us.

In terrestrial analog news, I will be heading to the Ries Crater in Nordlingen, Germany, after the Meteoritical Society meeting this summer. Ries is a well-preserved 24-km diameter, 15 Ma crater with post-impact lacustrine layers inside and fantastic outcrops of ejecta. The Ries ejecta may be a good analog to Martian double-layered ejecta deposits. There is an upper ejecta layer (suevite) which is a mix of deep material and impact melt, overlying a lower layer (the Bunte breccia) which is an interesting unit formed when the first (shallow) ejecta was ballistically emplaced and churned up the substrate, mobilizing it and causing a radial flow. It is rumored there are distal parts of the Bunte breccia containing crossbeds and lapilli that may be potentially interesting to compare with proposed origins of Meridiani and/or layers in the Inner Basin. Cool!

No comments: