Ghostly photos from NASA's Curiosity rover reveal beautiful, rare clouds and the first sun rays ever spotted on Mars

• NASA's Curiosity rover on Mars snapped the first clear photo of rays of sunlight illuminating Martian clouds.
• The sun rays beamed through a bank of Mars clouds that NASA says could be made of dry ice.
• The rover also snapped a picture of an iridescent cloud, shaped like a feather. 

NASA's Curiosity rover snapped the first clear picture of sun rays on Mars, which looks like a ghostly white-tinged sunset.

The rover took the ethereal photo on February 2, as the sun set behind a group of twilight clouds. These clouds hang at an unusually high altitude, which suggests they are probably made of carbon dioxide ice — also known as dry ice. NASA released the eerie image on Monday.

The sun's rays shine through the alien clouds, illuminating them with muted hues of green and pink.

Curiosity also captured a feather-shaped iridescent cloud hanging over Mars that appears to glow pink, green, and blue, in the image below.

"Where we see iridescence, it means a cloud's particle sizes are identical to their neighbors in each part of the cloud," atmospheric scientist Mark Lemmon said in the release. "By looking at color transitions, we're seeing particle size changing across the cloud. That tells us about the way the cloud is evolving and how its particles are changing size over time."

Both brilliant pictures were assembled from a series of 28 images that the rover sent back to Earth, and they were edited to "emphasize the highlights," according to NASA.

The sunset portraits expand on a survey the Curiosity rover conducted in 2021, where it watched pearly, shining twilight clouds pass overhead. 

The new survey relies more on Curiosity's color camera. The observations began in January and run until mid-March, so Curiosity should be sending NASA scientists lots of new information about these spectacular clouds.

Clouds are rare on Mars, since there isn't much water in the planet's atmosphere. Martian air has just 1% the density of Earth's atmosphere. When clouds do appear, it's mostly around the Martian equator during the coldest part of its year, when the planet's orbit takes it furthest from the sun.