A new video edited from submitted photos from NASA’s Curiosity rover shows red-green clouds floating across Mars’ sky, forming patterns similar to Earth’s. Studying the formation and location of these clouds helps scientists better understand their impact on the Red Planet’s climate.
Did you know that Mars has *iridescent* clouds?
Spotted by the @MarsCuriosity rover, these unique clouds are made of carbon dioxide ice and are only observed at twilight. What this helps us learn about the Red Planet: https://t.co/Snqyo49n1W pic.twitter.com/anXG7hf61K
— NASA JPL (@NASAJPL) February 12, 2025
Images taken on January 17, 2025, by one of Curiosity’s cameras show so-called twilight clouds. They are located high in the sky, where they are still illuminated by the Sun even when it is night on the surface of Mars. These clouds are composed of carbon dioxide crystals, or dry ice, and float 60-80 kilometers above the surface. Ice forms where the temperature is so low that the gas condenses.
The camera captured the ice crystals falling down to form white plumes. At an altitude of about 50 km, these plumes disappear as they vaporize due to rising temperatures. The photos were taken in 16 minutes and sped up 480 times to create the video.
What is known about clouds on Mars?
Twilight clouds usually appear in early autumn in the Southern Hemisphere. They were first recorded in 1997 during the Pathfinder mission north of the equator. Such clouds only became noticeable to Curiosity in 2019 — seven years after it landed in Gale Crater.
Researchers still can’t explain why these clouds only appear in certain places. For example, the Perseverance rover in the Perseverance crater in the Northern Hemisphere has not detected any twilight clouds at all. According to scientist Mark Lemmon, something in the atmosphere cools these areas enough to form ice. This may be due to atmospheric fluctuations that can lower the temperature.
Map of Martian clouds
In September 2024, scientists unveiled the largest map of clouds on Mars, based on two decades of observations by the European Space Agency’s Mars Express orbiter. It depicts a variety of cloud shapes, some of which are unparalleled on Earth.
“The clouds on Mars are just as spectacular as those we see on Earth,” noted planetary geologist Daniela Tirsch. But it remains a mystery why certain regions of Mars are more prone to cloud formation than others.
Studies of the Martian atmosphere continue, and each new discovery helps expand understanding of the planet’s climate.
We previously reported on how Perseverance spotted ominous signs of an approaching cataclysm on Mars.
According to Space
