NASA‘s Mars Curiosity rover has captured shining clouds on the Red Planet, which arrived earlier and formed higher than expected.

The atmosphere on Mars is usually thin, dry and cloudy days are rare. And clouds are typically found at the planet’s equator in the coldest time of year, when Mars is the farthest from the Sun in its oval-shaped orbit. But the scientists noticed clouds forming over NASA’s Curiosity rover earlier than expected, one full Martian year ago – two Earth years.

In late January this year, the team started documenting these “early” clouds. The images show wispy puffs filled with ice crystals that scattered light from the setting Sun, some of them shimmering with colour.

The rover’s Mast Camera, or Mastcam snapped colour images and the iridescent, or “mother of pearl” clouds on March 5, 2021, the 3,048th Martian day, or sol, of the mission. “If you see a cloud with a shimmery pastel set of colors in it, that’s because the cloud particles are all nearly identical in size. That’s usually happening just after the clouds have formed and have all grown at the same rate,” said Mark Lemmon, an atmospheric scientist with the Space Science Institute in Boulder, Colorado.

These clouds are among the more colorful things on the Red Planet, Lemmon added. If you were skygazing next to Curiosity, you could see the colours with the naked eye, although they’d be faint.