NASA's frosty Martian dunes spark hope for past life signs
Although the beans in the photo look like beans, the probe actually captured images of large frozen dunes on Mars. NASA has just shared this discovery, which scientists believe may indicate that life could have existed there.
The Mars Reconnaissance Orbiter (MRO) photographed the Martian dunes in the northern hemisphere of the Red Planet from above. The images, taken by the High-Resolution Imaging Science Experiment (HiRISE) camera during a flyover of the icy formations, allow researchers to explore whether life previously existed on Mars.
Martian dunes are frosted, but their ice is not made of water
Although the photos were taken earlier, NASA shared this discovery in September 2022. Scientists have determined so far that while the frost on these dunes consists of carbon dioxide and not water, it still affects the likelihood that water existed on Mars for a considerable period in the past, according to NASA. This discovery renews hope for discovering earlier or existing forms of life. The photographs of the frost-covered dunes help scientists assess whether water existed on the planet's surface for long enough to allow life to evolve and survive on Mars.
Why is CO2 ice on Mars? The amount of carbon dioxide on the Red Planet relates to its tilt towards the Sun. When Mars is tilted sufficiently, carbon dioxide ice converts to gas on a large scale, creating a thicker atmosphere across the entire planet. This denser atmosphere might have been enough to sustain liquid water for a significant period. Understanding how carbon dioxide frost forms and dissipates in current Martian conditions enables scientists to predict Mars's past climate better. If there were periods when the climate supported stable liquid water, there is a high probability that Mars could have sustained microbiological life — and perhaps it still harbors life somewhere.
The dunes in the photo are coated with a layer of carbon dioxide frost, but only during the winter in Mars's northern hemisphere. Remarkably, Martian dunes migrate like dunes on Earth: wind blows the sand and accumulates it elsewhere. Martian sand mainly consists of basalt, which is crushed volcanic rock material. According to NASA, recent studies have shown that the winter frost halts the movement of these sand grains, keeping the dunes stationary until the spring thaw. This discovery provides clues about past conditions on Mars and the potential for life to have existed there.
Ice frost halts the movement of wandering Martian dunes
By observing the dunes on Mars and studying how carbon dioxide frost appears and disappears under current conditions, scientists can better predict the past climate on the Red Planet. Research into how frost changes with the seasons can also help scientists identify geological formations caused by carbon dioxide, revealing more details about the planet's shifting climate. If there were periods when the climate supported stable liquid water, there is a high probability that Mars could have supported microbiological life — and it may even still be hiding somewhere.
