Water frost has been discovered on some of the solar system's tallest volcanoes. The cold conditions were observed on top of the Tharsis volcanoes, which are located near Mars's equator.
Scientists previously assumed frost could not exist on this portion of Mars, but this discovery demonstrates that ice is not limited to the north and south polar caps.
These giants are crowned by huge calderas, which are bowl-shaped depressions formed by the collapse of the volcano's top following a powerful eruption.
The calderas' sheer size - up to 75 miles (121 km) across - creates a unique microclimate within them. Researchers used cameras on Mars spacecraft to detect morning frost growing inside the calderas for the first time.
The discovery was made by the European Space Agency's (ESA) ExoMars Trace Gas Orbiter. It was later confirmed by another TGO instrument and the European Space Agency's Mars Express.
The amount of frost on the volcanoes is estimated to be roughly 150,000 tonnes of water, which is equivalent to the amount of water in almost 60 Olympic-sized swimming pools.
Space exploration: Water frost found on top of Mars’ volcanoes
