The atmosphere on Mars is very thin and made of 96 percent carbon dioxide, and hence, the formation of thick clouds is not possible. Hence, the clouds on Mars are light. They are formed in different ways.
According to experts, the cloud formation on Mars likely occurs due to the dust formed when space debris hits its atmosphere.
On Mars, clouds are typically found at the planet’s equator in the coldest time of year. But one full Martian year ago – two Earth years – scientists noticed clouds forming over NASA‘s Curiosity rover earlier than expected.
This year, the clouds appeared in late January. Since then, scientists are documenting these “early” clouds. What came about are images of wispy puffs loaded up with ice crystals that dissipated light from the setting sun, some of them sparkling with color. Other than spectacular showcases, such pictures assist scientists with seeing how clouds form on Mars and why these new ones are different.
What’s more, NASA’s Curiosity team has discovered that the early-arrival clouds are actually at higher altitudes than is typical. It signifies that they are likely made of frozen carbon dioxide or dry ice.
Usually, clouds on Mars floats about 37 miles (60 kilometers) in the sky. They are loaded up with water ice.
With Curiosity’s black-and-white navigation cameras, scientists can easily see fine, rippling structures of these clouds. But it’s the color images from the rover’s Mast Camera or Mastcam that shine – literally.
Just because the images were captured just after the sunset, their ice crystals catch the fading light, causing them to appear to glow against the darkening sky.
These twilight clouds, also known as “noctilucent” (Latin for “night-shining”) clouds, grow brighter as they fill with crystals, then darken after the Sun’s position in the sky drops below their altitude. This is just one helpful clue scientists use to determine how high they are.
Mark Lemmon, an atmospheric scientist with the Space Science Institute in Boulder, Colorado, said, “Even more stunning are iridescent, or “mother of pearl” clouds. 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.”
“These clouds are among the more colorful things on the Red Planet. If you were skygazing next to Curiosity, you could see the colors with the naked eye, although they’d be faint.”
“I always marvel at the colors that show up: reds and greens and blues and purples. It’s cool to see something shining with lots of color on Mars.”