These three images are of Phobos, Mars’s larger moon, passing directly in front of the sun. They were taken about three seconds apart by the Curiosity rover. Curiosity photographed this eclipse with the telephoto-lens camera of the rover’s Mast Camera pair on 17 August, 2013, the 369th Martian day (or sol) of its mission on Mars. Because this eclipse occurred near mid-day at Curiosity‘s location on Mars, Phobos was nearly overhead, closer to the rover than it would have been earlier in the morning or later in the afternoon. This timing made Phobos’ silhouette relatively large against the sun—as close to a total eclipse of the sun as is possible from Mars.
Image Credit: NASA