Curiosity Views Twilight Clouds

NASA's Curiosity Mars rover used its left Mast Camera, or Mastcam, to capture these drifting noctilucent, or twilight, clouds on Jan. 17, 2025, the 4,426th Martian day, or sol, of the mission. The left Mastcam has a stuck color filter wheel, which is why part of the imagery appears cut off in three corners. The original recording taken by Curiosity was 16 minutes; this video has been speeded up by about 480 times (and it loops four times). The clouds at the top of the frame, including the falling white plumes, are made of carbon dioxide ice. The plumes are an estimated 37 to 50 miles (60 to 80 kilometers) above the Martian surface; they could fall as low as 31 miles (50 kilometers) above the surface before they would evaporate due to rising temperatures. In the lower half of the frame at the beginning of the video, a different set of very faint clouds is visible. These are water-ice clouds are hovering at roughly 31 miles (50 kilometers) in altitude. The brightness has been stretched to make certain colors more visible in this enhanced-color imagery. This is the fourth Mars year that twilight clouds have been observed by Curiosity; previous observations were made in 2019, 2021, and 2023. Animation available at https://photojournal.jpl.nasa.gov/catalog/PIA26519