Morning Frosts Fill Martian Volcanoes with 150,000 Tons of Water Ice

The crew of SYFY’s The Ark (Season 2 debuts July 17!) is headed for another world, a little planet around the nearby star Proxima centauri. When (if) they get there, they’ll have only what they’ve brought with them, and whatever they can scrape together in their new environment. Here in the real world, astronauts are soon headed back for the Moon as a jumping off point for Mars, and they’ll have the same limitations as those fictional explorers.

Fortunately for future astronauts and for the scientific endeavor, new observations of the Red Planet reveal water ice in the form of frost, nestled inside volcanic calderas near the Martian equator. The discovery is the result of a collaboration between the European Space Agency’s (ESA) Mars Express orbiter and ExoMars program, and the results were published in the journal Nature Geoscience.

For More on Mars:
The ESA's ExoMars Orbiter Captures Swarms of Dark "Spiders" on the Surface of Mars
NASA Wants Its Space Rocks Stat, Announces Update for Mars Sample Return Mission
Giant "Hidden" Volcano Taller Than Everest Discovered on Mars

ESA Spacecrafts Detect Frost Inside Martian Volcanoes

This image was captured by NASA's HiRISE and shows a crater in the southern hemisphere of Mars, during late Martian winter, with frost on all of its south-facing slopes. Photo: NASA/JPL-Caltech/University Of Arizona

Mars Express arrived in Mars' orbit back in 2004 and it’s spent the last two decades taking high-definition images and mapping the surface. ExoMars is a two-part ESA program composed of the Trace Gas Orbiter (TGO), currently in orbit around the planet, and the Rosalind Franklin rover, planned for launch in 2028. The program’s primary mission is searching for evidence of life in the Martian past.

Together, the two spacecrafts provided new observations which confirm the existence of transient water frost atop Martian volcanoes. Frost was first glimpsed using the TGO’s CaSSIS (Colour and Stereo Surface Imaging System) instrument and later confirmed using the TGO’s NOMAD (Nadir and Occultation for Mars Discovery) spectrometer and the HRSC (High Resolution Stereo Camera) aboard Mars Express. Frost was observed inside multiple volcanoes including the record-breaking Olympus Mons, which stands roughly three times higher than Everest at its peak. Finding water ice there is notable because those volcanoes are located along the Martian equator, where temperatures are at their warmest. Previously, water ice had only been observed at more polar regions (pictured above).

“We thought it was impossible for frost to form around Mars’s equator, as the mix of sunshine and thin atmosphere keeps temperatures relatively high at both surface and mountaintop – unlike what we see on Earth, where you might expect to see frosty peaks,” said lead author Adomas Valantinas, in a statement.

The frost shows up for a few hours around sunrise, before the sunshine creeps inside the caldera and melts it. That helps to explain why no one noticed it before, you have to know precisely when and where to look or else you’ll miss it. The frost is estimated to be only about as thick as a human hair but spread across huge areas. For context, Olympus Mons is about the same size as the state of Arizona at its base. Even at its peak, the caldera stretches 50 miles from one side to the other. These transient frosts carry an estimated 150,000 tons of water (enough to fill 60 Olympic pools) back and forth from the surface to the atmosphere every day. Here’s how it happens.

This image shows Olympus Mons, the tallest volcano in the entire Solar System. It was obtained by the High Resolution Stereo Camera aboard ESA’s Mars Express, and taken as part of new research revealing water frost for the first time near Mars’s equator (a part of the planet where it was thought improbable for frost to exist). Photo: ESA/DLR/FU Berlin

These volcanoes are huge blemishes on the planet’s face, towering miles above the surface. When they erupted in the past, the explosive force carved out calderas, cratered bowls at the peak which remain to this day. Thin Martian winds carry comparatively moist air up the slope, from the surface. As those winds rise, the water condenses and falls into the caldera where the shadows protect it from sunlight, at least for a while.

“Mars’s low atmospheric pressure creates an unfamiliar situation where the planet's mountaintops aren’t usually colder than its plains – but it seems that moist air blowing up mountain slopes can still condense into frost, a decidedly Earth-like phenomenon,” said ESA project scientist Colin Wilson.

This discovery provides a clearer view of the Martian atmospheric cycle, including how, when, and where water is transported. That’s crucial information for future crewed missions. Astronauts will need water for the usual activities like drinking, cooking, and cleaning, but they could also split it into hydrogen and oxygen for use as fuel. The crew of The Ark can only hope to find a world as welcoming as Mars when they finally get where they’re going.

Season 2 of the Ark debuts July 17 on SYFY! Catch up with entire first season, streaming now on Peacock.