Scientists uncover secrets of mysterious 1,100 km-long Mars cloud

In 2018, some corners of the Internet thought there might be a massive volcanic eruption on Mars, but it was a trick of the eye. A long, thin a cloud appears above the Arsia Mons volcano on Mars seasonally, and now scientists have gotten better insight into how it forms and dissipates.

A team of researchers studied the life cycle of the cloud using a camera dubbed “the Mars webcam” on the European Space Agency’s Mars Express spacecraft.

The ephemeral nature of the cloud and the orbits of spacecraft around Mars made the formation difficult to study. The Mars webcam – more formally known as the visual surveillance camera – has the resolution of a 2003 computer webcam, but it also has a wide field of view, which is why the researchers put it in service to study the cloud.

The team published an article on their findings late last year in the journal JGR Planets.

“Many Mars orbiters cannot begin to observe this part of the surface until the afternoon due to the properties of their orbits, so this is really the first detailed exploration of this interesting feature,” said the co- study author Agustin Sánchez-Lavega from the University of the Basque Country in an ESA statement on Tuesday.

The cloud appears during the Martian spring and can extend up to 1,800 kilometers in length. “It is the largest ‘orographic’ cloud ever seen on Mars, which means it forms as a result of wind driven upward by topographic features (such as mountains or volcanoes) on a planetary surface “said ESA.

The cloud goes through a daily growth cycle that begins before sunrise and exhibits a rapid rate of expansion as it expands from Arsia Mons. It evaporates later as the day warms up.

We have high clouds on Earth, but they don’t reach the wild lengths of it on Mars. “Understanding this cloud gives us the exciting opportunity to try to replicate the formation of the cloud with models – models that will improve our knowledge of climate systems on Mars and on Earth,” said Sánchez-Lavega.

The cloud of Arsia Mons is one of the wonders of Mars. It may be less of a mystery now, but it’s just as fascinating as ever.

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