As the Curiosity rover explores its way around Mars, it isn’t only looking down at the martian rocks and regolith — it is also looking up at the martian sky. Like Earth, Mars has its own seasonal weather patterns, but with its different atmosphere that weather can include some unusual phenomena, such as striking colorful clouds.
A recent video created from images captured by Curiosity shows clouds tinted red and green flowing though the sky over Mars. Captured using the rover’s Mastcam instrument on January 17, 2025, the video shows the clouds during twilight on the red planet.
Credit: NASA/JPL-Caltech/MSSS/SSI
These clouds have been observed before, as Mars sometimes sees iridescent ‘mother of pearl’ clouds due to the way light from the sun is scattered. Though Mars has a very thin atmosphere, at just 1% of the density of Earth’s atmosphere, it can still have clouds made of water ice or carbon dioxide ice. It is these carbon dioxide clouds, which form at high altitudes, that show the coloful effects.
“I’ll always remember the first time I saw those iridescent clouds and was sure at first it was some color artifact,” said researcher Mark Lemmon of the Space Science Institute. “Now it’s become so predictable that we can plan our shots in advance; the clouds show up at exactly the same time of year.”
The shimmering clouds can be spotted in Mars’s southern hemisphere, where Curiosity is located, during the early fall period. Observations each year have helped researchers to learn more about them, but it’s still not clear why these clouds form over the Gale Crater, where Curiosity is, and not in other locations. The Perseverance rover, for example, is exploring in the Jezero Crater in the planet’s northern hemisphere but has never seen any carbon dioxide clouds.
The researchers suspect that certain regions of the planet may form these clouds more easily due to gravity waves affecting the atmosphere. “Carbon dioxide was not expected to be condensing into ice here, so something is cooling it to the point that it could happen,” Lemmon said. “But Martian gravity waves are not fully understood and we’re not entirely sure what is causing twilight clouds to form in one place but not another.”
After 13 suborbital test flights and more than $15 billion in development costs, SpaceX's Starship has finally reached orbit. The 407-foot megarocket, the most powerful ever built, lifted off from Starbase, Texas, on Monday and delivered its first real payload on it's 14th attempt. The celebration came with an asterisk, though, since SpaceX had to cut the planned 10-hour mission to roughly three hours.
https://twitter.com/SpaceX/status/2104601695711904180
SpaceX is finally ready to give Starship its biggest test yet. The company says the massive rocket's 14th test flight is scheduled for September 22, when it will attempt to put the upper stage into Earth orbit for the first time. The launch is currently pending regulatory approval, with a 75-minute window opening at 7:15 a.m. CT.
Starship has 26 Starlink satellites to deliver
For decades, humanity has looked up at the Moon and wondered what it would be like to live on it. Think sprawling cities, factories, research centers, and permanent human settlements. Unfortunately, there is one fairly fundamental problem with that vision.
A new study published in Frontiers in Space Technologies argues that even the Moon's potentially enormous reserves of frozen water may be nowhere near enough to support city-sized populations sustainably. Researchers Martin Elvis and Jonathan McDowell estimate that the permanently shadowed regions near the lunar poles could contain roughly one billion tons of water. It sounds like an extraordinary amount until you put a million thirsty humans next to it.