As part of a multi-mission campaign, NASA's Curiosity rover is observing Martian moon transits, the first of which involved the moon Phobos grazing the sun's disk. The event was observed on Martian day, or sol, 37 (September 13, 2012) using Curiosity's Mast Camera, or Mastcam, equipped with special filters for directly observing the sun. This image layout compares views from the Mastcam 34-millimeter lens (left) and the Mastcam 100-millimeter lens, which is designed to take zoomed-in shots with about three times higher resolution. These images were taken about 18 seconds apart.