Space & Astronomy

Strange 1,500km-long cloud spotted on Mars

By T.K. Randall
November 1, 2018

Image Credit: NASA / JPL The phenomenon, which was first spotted back in September, is situated next to Arsia Mons - a volcano - leading some to speculate that a volcanic eruption may have been taking place.

As it happens however, Arsia Mons has not been volcanically active for over 50 million years.

The answer, it turns out, is that the cloud, which is comprised of water ice, was formed from the interaction between the Martian air and the southwest slope of the volcano.It is a phenomenon known as a 'lee cloud' owing to its formation from the volcano's leeward slope.

"The cloud's appearance varies throughout the martian day, growing in length during local morning downwind of the volcano, almost parallel to the equator, and reaching such an impressive size that could make it visible even to telescopes on Earth," ESA wrote.

The formation of water-ice clouds is sensitive to the amount of dust in the atmosphere (remember the #Marsstorm in June/July?) ☁️ The cloud was also observed with OMEGA (left) & High Resolution Stereo Camera (right) on #Mars Express, providing extra #data to study the phenomenon pic.twitter.com/OSGHfEKSw0

— ESA Science (@esascience) October 25, 2018

Source: The Weather Channel

Tags: Mars, Cloud