NASA’s Curiosity rover has captured rare and beautiful images of “twilight” clouds on Mars, shedding light on a long-standing Martian mystery. The cloud formations are similar to those seen on Earth during the summer months, but occur at higher altitudes and lower temperatures on the Red Planet.
The images were taken using the rover’s Mastcam instrument over 16 minutes on January 17, 2025, revealing colourful red and green clouds in the Martian sky. Scientists believe these clouds are made of water ice and carbon dioxide ice, with the latter being responsible for their iridescent appearance.
However, what’s puzzling planetary scientists is why noctilucent clouds seem to occur only in one location on Mars. The Curiosity rover is located on Mount Sharp in Gale Crater, south of the Martian equator, while other rovers, such as NASA’s Perseverance rover, have not seen these clouds since its 2021 landing.
Theories suggest that gravity waves may be responsible for the formation of noctilucent clouds in certain locations. Carbon dioxide was not expected to condense into ice, so something must be cooling it down to make it happen. However, the Martian gravity waves are not fully understood, and scientists are still trying to figure out what causes these clouds to form in one place but not another.
The images captured by Curiosity provide valuable insights into the Martian atmosphere and its unique features. As scientists continue to study these phenomenon, they may uncover more secrets about our neighbouring planet.
Source: https://www.skyatnightmagazine.com/news/curiosity-captures-noctilucent-clouds-mars