Webb telescope peeks into frozen heart of a space cloud
Thanks to photographers, we know that snowflakes on Earth are unique and six-sided.
Under a microscope, Martian snowflakes would probably look a little different.
“Because carbon dioxide ice has a symmetry of four, we know that the pieces of dry ice will be cube-shaped,” Piqueux said.
“Thanks to the Mars Climate Sounder, we can tell that these snowflakes will be smaller than the width of a human hair.”
Ice and carbon dioxide-based snow also form on Mars, and they can form away from the poles. The Odyssey orbiter (which entered Mars orbit in 2001) observed frost forming in sunlight and turning into a gas, while the Viking landers observed icy frost on Mars in the 1970s.
At the end of winter, the weather’s ice buildup can melt and turn into a gas, creating unique shapes that have reminded NASA scientists of Swiss cheese, Dalmatian spots, scrambled eggs, spiders and other unusual formations .
During the winter in Jezero Crater, recent high temperatures have been about −13 °C, with lows of about −84 °C.
Meanwhile, in Gale Crater in the southern hemisphere near the Martian equator, the Curiosity rover, which landed on Mars in 2012, is experiencing a high of -15 and a low of -76.
The seasons on Mars are long because the planet’s oval-shaped orbit around the Sun means that a single Martian year is 687 days, or about two Earth years.
NASA scientists celebrated the Martian New Year on December 26, coinciding with the arrival of the spring equinox in the Northern Hemisphere.
According to a post on the NASA Mars Facebook page, “Scientists count Martian years starting from the planet’s northern spring equinox that occurred in 1955 — an arbitrary point, but it’s useful for a system.”
“Calculating Mars years helps scientists keep track of long-term observations such as weather data collected by NASA spacecraft over the decades.”