Hoping for a white Christmas this year? Well, even if there’s no snow where you live, at least you can enjoy these images of a “winter” wonderland online Mars.
Photographed by the German-made High Resolution Stereo Camera (HRSC) aboard the European Space Agency (ESA) Mars Express The orbiter will be launched in June 2022 by NASA’s NASA Mars Reconnaissance Orbiter The images were taken in September 2022 using the High-Resolution Imaging Science Experiment (HiRISE) camera and show snowy scenes in the Australe Scopuli region of Australia. Marsnear the Earth’s South Pole.
But the “snow” seen here is very different from the “snow” we see Earth.
In fact, it’s carbon dioxide ice, and at the South Pole of Mars, there’s There is a 26-foot-thick (8-meter-thick) layer of water year-round. (These photos were actually taken near the summer solstice, not winter – it’s cold here year-round.)
So why does it appear that there is only a layer of “snow” in these images? Those darker areas are layers of dust that have settled on the ice. This dust is usually found deep within the ice, but seasonal processes bring some of it to the surface.
NASA’s Mars Reconnaissance Orbiter also saw winter frost on the sides of Martian dunes. NASA says this frost can prevent erosion Writekeeping the dust that makes up the dunes in place until the spring thaw season.
When sunlight warms carbon dioxide ice at Mars’ south pole in the summer, the ice begins to sublimate, or change directly from solid to vapor. When it does this, some trapped gas forms within the ice.
Eventually, the pressure increases enough to produce a slight eruption of gas strong enough to blast the black dust found under the ice into the air. When dust falls back onto the surface, the wind carries it into these swirling patterns. (Side note: A similar process creates Spider-like features discovered on Mars surface.)
So what appear to be beautiful pastoral winter scenes in these Mars Express images are actually dynamic summer scenes, with gas jets spewing dust across the surface. Hey, at least it’s still cold outside — just -193°F (-125°C).