Mars: turns into a spooky winter wonderland – check out the photos and videos

It’s late winter in the northern hemisphere of Mars, as the Perseverance rover and Ingenuity helicopter explore an ancient river delta that fed Jezero Crater billions of years ago.

Dust determines the weather on the planet. It usually heralds the coming of winter, accompanied by snow, sleet and ice. At the planet’s poles, the temperature can drop to -123 degrees Celsius.

There are two types of snow on Mars. One is the kind that is on land and consists of frozen water. Mars’ thin air and sub-zero temperatures mean that conventional snow vaporizes, or turns from a solid directly into a gas, before hitting the ground.

The other type of Martian snow is carbon dioxide-based. It’s called dry ice and it can “land” on the surface. A few meters of snow tends to fall in the flat areas near the poles.

“It’s falling low enough that you could snowshoe across it,” said Sylvain Becchio, a scientist at NASA’s Gas Propulsion Laboratory in Pasadena, California. “If you’re looking to ski, you’ll have to go to a crater or a slope, where snow can build up on an inclined surface.”

So far, no spacecraft or spacecraft have been able to see snow falling on the Red Planet because the weather phenomenon only occurs at night at the poles, under the cloud cover. Spacecraft cameras can’t see through clouds, and no robotic exploration vehicles have been developed that can withstand the freezing temperatures at the poles.

However, the Mars Climate Probe on the Mars Reconnaissance Orbiter can detect light that is invisible to the human eye and detect dry ice. The Phoenix lander, which arrived at Mars in 2008, used one of its laser instruments to detect snow in a spot about 1,609 kilometers from its north pole.

Snowflakes on Earth are unique and have six faces. But, under a microscope, Martian snowflakes probably look a little different. “Because carbon dioxide ice has four times the symmetry, we know that the dry snowflakes will be cube-shaped,” Becchio said. “Thanks to the Martian climate safer, we can say that these snowflakes will be smaller than the width of a human hair.”

Carbon dioxide-based ice and frost can also occur far from the poles. Watch Odyssey form frost and turn into gas in the sunlight.

At the end of winter, the accumulated ice can melt and turn into gas, creating unique shapes that remind NASA scientists of Swiss cheese, Dalmatian spots, fried eggs, spiders, and other unusual formations.

Seasons on Mars tend to be longer because the planet’s elliptical orbit around the sun means that a Martian year lasts 687 days, or roughly two Earth years. NASA scientists celebrated the Martian New Year on December 26, which coincided with the arrival of the vernal equinox in the northern hemisphere.