Gusev Crater's Horizon - Soles 497/500 (Approximate True Colors; credits: NASA/JPL-Caltech)

Original NASA caption:"More than 1,5 years into their exploration of Mars, both of NASA's Mars Exploration Rovers continue to send a cornucopia of images to Earth. The results are so spectacular that Deputy Project Manager John Callas recently described them as "an embarrassment of riches". Spirit produced this image mosaic, nicknamed the "Whale Panorama", two-thirds of the way to the summit of Husband Hill, where the Rover investigated martian rocks. On the right side of the panorama is a tilted layer of rocks dubbed "Larry's Outcrop", one of several tilted outcrops that scientists examined in April, 2005. They used spatial information to create geologic maps showing the compass orientation and degree of tilting of rock formations in the vicinity. Such information is key to geologic fieldwork because it helps establish if rock layers have been warped since they formed".