Scientists have now identified water frost on the summits of several large Martian volcanoes, indicating potential habitable zones for future missions to the Red Planet.
This discovery, led by Dr. Adomas Valantinas of the University of Bern, is an important milestone toward understanding Mars' climate and water cycle, which is critical for future human exploration.
MOLA-based still image showing Martian topography of Olympus Mons as both color and elevation.Image via NASA
How Scientists Found the Water Frosts on Mars
An international research team, led by Dr. Adomas Valantinas, utilized high-resolution images from the European Space Agency's Trace Gas Orbiter (TGO) to detect transient morning frost deposits on the calderas of Mars' largest volcanoes.
The discovery was made through images taken since April 2018 by the Color and Stereo Surface Imaging System (CaSSIS) onboard the TGO.
These volcanoes, situated in the Tharsis region near Mars' equator, are known for their towering heights, with Olympus Mons, rising to 21 kilometers above the surrounding plains or three times higher than Mt. Everest.
How Water Frosts Formed on Mars
High-resolution color images from CaSSIS revealed bluish frost on the volcanic summits during the early Martian morning, which vanishes by afternoon.
This frost, forming during colder Martian seasons, is believed to originate from atmospheric water vapor rather than volcanic activity. Follow-up observations using the Mars Express orbiter and the NOMAD spectrometer confirmed the presence of water frost.
Climate models indicated that early morning temperatures on the volcano summits are low enough for water frost to form, but not carbon dioxide frost. This daily cycle of condensation and evaporation suggests an active water cycle on Mars.
Valantinas explains, "Upslope winds carry air containing water vapor up from the lowlands. As this air reaches higher altitudes, it cools, causing condensation. This is a familiar phenomenon on both Earth and Mars."
What the Discovery Means for Future Mars Exploration Missions
Aynur Zakirov from Pixabay
Understanding this water cycle is essential for assessing Mars' habitability and planning future human missions. The frost forms due to the unique microclimate of the Tharsis volcanoes, where local conditions allow water to condense at night and evaporate during the day. This process is part of a broader water cycle on Mars, where water vapor moves between the atmosphere and the surface.
Despite being thin, likely only one-hundredth of a millimeter thick, the frost patches cover a vast area and represent an exchange of about 150,000 tonnes of water between the surface and atmosphere each day during cold seasons.
This amount is roughly equivalent to the volume of water in 60 Olympic swimming pools. Nicolas Thomas, another key researcher, highlights the importance of this discovery: "Understanding where water can be found and how it moves between reservoirs is relevant for many aspects of Mars exploration."
