"The thing about rock varnishes is the mechanism behind why they form is not clearly understood," Lanza said. "Some people believe that rock varnish results from an interaction of small amounts of water from humidity in the air with the surface of rocksa chemical reaction that forms a coating. Others think there could be a biological component to the formation of rock varnishes, such as bacteria or fungi that interact with dust on the rocks and excrete varnish components onto the surface."
Lanza is quick to point out that she's making no concrete claim as to the identity or origin of whatever is being seen during the first five shots of each ChemCam sampling. The common signature from the first five blasts could indeed be entirely surface dust, or it could be a rock coating or a rind formed by natural weathering processes.
As the mission progresses, Lanza hopes that integrating other instruments aboard Curiosity with ChemCam sampling activities could help rule out unknowns such as surface dust, while careful experiments here on Earth could provide crucial clues for solving the Martian mystery of the first five shots.
"If we can find a reason for this widespread alteration of the surface of Martian rocks, it will tell us something about the Martian environment and the amount of water present there," Lanza said. "It will also allow us to make the argument that what we're seeing is the result of some kind of current geological process, which could give us ins
|Contact: James E. Rickman|
DOE/Los Alamos National Laboratory