NASA's Astronomy Picture of the Day for 3 October 2026 shows one of the best-known self-portraits from Mars. In it, the Curiosity rover stands on Vera Rubin Ridge, a rocky ridge on the lower slopes of Mount Sharp inside Gale Crater.
The picture is not a single shot. Curiosity stitched it together from many frames taken by its MAHLI camera, which sits at the end of the robotic arm. Because of how the frames overlap, the arm mostly disappears from the final mosaic. The images were taken in early 2018, while the rover was exploring the ridge.
Scientists wanted to study the ridge because data from orbit showed it holds a lot of hematite. This iron oxide usually forms when water is present. Its layered rocks helped the team work out how ancient lakes and groundwater shaped the crater billions of years ago.
The ridge is named after American astronomer Vera Rubin. Her measurements of how galaxies rotate gave key evidence for dark matter.
