For the first time, this strange single elongated cloud was captured by the Mars Express orbiter on September 13, 2018.
For more than a month, scientists have been observing this cloud, which continues to hang steadily in the same place, and hypothesize about its nature, according to the European Space Agency.
An elongated cloud of deep white color hangs next to Mount Arsia.
It is a long-extinct shield volcano 20 km high, located in the province of Farsis and is the largest volcano in the solar system.
However, scientists do not associate the cloud with volcanic activity. According to their version, most likely the cloud consists of water vapor and it was formed due to suitable terrain conditions.
The leeward slope of the volcano interacts in a special way with atmospheric flows and an effect arises, which in science is called orographic or leeward cloudiness. This can sometimes be observed on Earth.
The last image of the long white cloud so far was taken by the Mars Express camera on October 10. The cloud stretches for a whopping 1,500 kilometers in length.
Promotional video:
In this photo from September 21, it is clearly visible that the "head" of the cloud hangs over the circular part of the relief of Mars. This is an extinct volcano, which is 250 kilometers wide.
According to the researchers, although the cloud hangs in one place, its length varies over the course of a Martian day, lengthening greatly in the morning. And then this cloud can be seen even with ground-based telescopes.
Below is a snapshot of the same cloud on September 17. The circular formations in the picture are extinct volcanoes.
