Trends on the Slopes of 'Endurance'
This graph shows how elements change in composition along the slopes of "Endurance Crater." The data were taken by the Mars Exploration Rover Opportunity's alpha particle X-ray spectrometer. While chlorine levels were found to significantly increase with crater depth, magnesium and sulfur concentrations significantly decreased. Because these latter two elements decrease in parallel, they probably represent magnesium sulfate that precipitated out of water.
Image Credit: NASA/JPL/Cornell/Max Planck Institute
+ Medium resolution version of this image
+ Print this image and caption