Composite image of Sun rays on Mars, captured by Curiosity rovers Mastcam on 2 February, 2023. These rays only appear near sunrise or sunset, and are known as crepuscular rays. This cloud is thought to be higher than most clouds on Mars. The conditions at such an altitude on Mars would suggest that this cloud is formed of carbon dioxide (dry ice). Clouds are relatively rare on Mars, only forming in certain areas when Mars is furthest from the Sun. Scientists hope to study clouds such as these, which appear earlier in the Martian year, to better understand how clouds form on Mars.