Planetary scientists were surprised to discover frost near Mars’ equator, a region previously thought to be too sunny and with a thin atmosphere to support frost or ice. The discovery was made by the European Space Agency’s ExoMars and Mars Express missions. The frost was found on the Tharsis volcanoes, which are the tallest volcanoes in the solar system, including Olympus Mons, which is three times taller than Mount Everest.
Lead author Adomas Valantinas, who made the discovery while a Ph.D. student at the University of Bern, Switzerland, and is now a postdoctoral researcher at Brown University in Providence, Rhode Island, expressed excitement about the finding. He explained that the presence of frost near Mars’ equator indicates exceptional processes at play that allow for its formation.
Unlike Earth, where frosty peaks are common, Mars has low atmospheric pressure, causing mountaintops to have similar temperatures to the plains. Scientists believe that moist air blowing up mountain slopes and condensing as frost in the calderas of the Tharsis volcanoes is creating a unique microclimate on Mars. The frost, equivalent to roughly 60 Olympic swimming pools, exists for a few hours around sunrise before evaporating in sunlight.
The discovery was made using observations from the ExoMars Trace Gas Orbiter (TGO) instruments CaSSIS and NOMAD, along with additional imaging by ESA’s Mars Express. While orbiters have been studying Mars for years, the unique microclimate was only recently observed due to the need to capture locations in the early morning when frost is present. Additionally, frost deposition is linked to colder Martian seasons, making the window for spotting it narrow.
Overall, the discovery of frost near Mars’ equator has opened up new possibilities for understanding the planet’s climate and geological processes in more detail. Scientists are excited about the implications of this finding and are eager to conduct further research to uncover the mysteries of Mars’ unique environment.