ENLARGE / Panoramic view from NASA’s Opportunity rover looking down the floor of Marathon Valley and out to the vast expense of Endeavour Crater. Marathon Valley holds significant deposits of water altered clay minerals. This composite photo mosaic shows the rover’s robotic arm reaching out at left to investigate Martian rocks […]


ENLARGE / This figure shows the characteristic ‘horseshoe’ pattern of Atlantic climate variability (top left panel), along with the time history of this pattern (bottom left). Most previous studies attribute this to changes in the ocean circulation. Our study compares climate models that include ocean circulation (top right) with climate models […]