Mars may have once closely resembled Earth with a rich atmosphere and running rivers, lakes and oceans. The winding canyons, dried up riverbeds and ancient shorelines crisscrossing the Martian landscape are all evidence of a wet past. Today, however, the Red Planet is an inhospitable desert with a paper-thin atmosphere and no magnetosphere to protect from deadly space radiation. So, what happened to Mars around 4.5 billion years ago, which explains the dire loss of water?
A new study published on April 10 by NASA scientists in the journal Nature, has proposed giant dust storms could be to blame.
On Mars, giant dust storms are a regular occurrence, which kick-up enough dust into the skies for telescopes on Earth to see them.
The Martian storms range in size and intensity but can span the length of entire continents and last for weeks at a time.
NASA scientists estimate at least one such storm rages across the Red Planet every single year.
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One of these dust storms grew to engulf the entirety of Mars in the summer of 2018, resulting in the tragic death of NASA’s Opportunity rover.
Geronimo Villanueva, a planetary scientist at NASA’s Goddard Space Flight Center, believes storms like this are key to cracking the mystery of Mars’ missing water.
He said: “The global dust storm may give us an explanation.”
According to the NASA expert, powerful dust storms can lift up water vapour into higher elevations from about 12 miles (20km) to at least 50 miles (80km) above the surface.
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When this happens, the dust storms disrupt the Red Planet’s natural water cycle, which prevents the water vapour from raining back down to the ground.
NASA explained: “On Earth H2O falls back down as rain or snow. The same process could have existed on Mars billions of years ago.”
When the water vapour reaches higher altitudes, intense solar radiation breaks up the H2O molecules, causing the individual hydrogen and oxygen atoms to escape into space.
Dr Villanueva said: “When you bring water to higher parts of the atmosphere, it gets blown away so much easier.”
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The incredible research was conducted with aid from the European Space Agency (ESA) and Russia’s space agency Roscosmos.
The researchers claim to have found proof of “receding water vapour” with the ExoMars Trace Gas Orbiter – a spacecraft managed by the ESA and Roscosmos.
In their study, the researchers wrote: “Global dust storms on Mars are rare but can affect the Martian atmosphere for several months.
“They can cause changes in atmospheric dynamics and inflation of the atmosphere, primarily owing to solar heating of the dust.
“In turn, changes in atmospheric dynamics can affect the distribution of atmospheric photochemistry and climate on Mars.”