Water frost has been discovered on the equator of Mars for the first time, in a region called the Tharsis area. Previously it was thought to be impossible for frost to form in Mars’ equatorial regions due to the temperatures.
The frost was spotted on the slopes of some large volcanoes in the Tharsis region, including Olympus Mons, Arsia Mons, Ascraeus Mons and Ceraunius Tholus.
The frost forms for a few hours around sunrise and then evaporates as temperatures rise. It is very thin, about as thick as a human hair. But it covers a large area of the volcanoes.
The frost is thought to form due to unique microclimates inside the large caldera hollows at the summits of the volcanoes. Winds blowing up the slopes bring moist air that condenses as frost in the cold, shadowed caldera areas.
This discovery was enabled by observations from the ExoMars Trace Gas Orbiter and Mars Express spacecraft, which can observe Mars at different times of day. It provides new insights into the water cycle on Mars and locations where water may exist.
The presence of frost in the equatorial region was unexpected and hints that exceptional atmospheric processes are allowing frost to form where previously thought impossible. This could impact models of water on Mars.
Source: Space
