Source: NASA/JPL-Caltech/MSSS/SSI, compiled by Claudia Hinz

On February 2, 2023, the 3,730th Martian sol, NASA’s Curiosity rover successfully captured images of noctilucent clouds and crepuscular rays shortly after sunset, projected onto thin clouds in the Martian atmosphere. The composite image is made up of 28 individual frames taken by the rover’s Mast Camera (Mastcam) and enhanced to improve the visibility of the phenomenon. This marked the first time such atmospheric features had been observed on Mars with such clarity.

The image was taken as part of an ongoing investigation into “noctilucent clouds” on Mars, which began in 2021. While most Martian clouds form no higher than 60 kilometers above the surface and are composed primarily of water ice, these clouds appear at much higher altitudes and within extremely cold atmospheric layers. This suggests that they are composed of carbon dioxide ice, or dry ice. The initial detection of a Martian halo on December 15, 2021, already indicated the presence of tenuous clouds in the Martian atmosphere consisting of fine ice crystals.