A strange long cloud has formed so many times over the same one Martian volcano that scientists have given up and baptized him.
Meet the extended cloud of Arsia Mons or AMEC. Its long bright path has become a familiar line above the peak, known as Arsia Mons, southeast of the more famous Olympus MonsAlthough the cloud comes and goes over the volcano, scientists say it was not formed by the volcano itself. And it’s time: Scientists involved in the orbit of the Mars Express in Europe have been waiting for it to reappear on its annual cycle.
“We were investigating this intriguing phenomenon and expected to see a similar cloud form around now,”
Photos: View of the Red Planet from the European Mars Express
“This elongated cloud forms everyone Martian year this season around the southern solstice and is repeated for 80 or more days, “said Hernandez-Bernal.” However, we still do not know if the clouds are always so impressive. “
So far, scientists have caught the cloud moving only 1,100 miles (1,800 kilometers), according to the ESA. The tail-like structure is made of water ice, and despite its location above Arsia Mons, it is not formed by the volcano itself, scientists said, but instead local winds interact with the topography.
And the Arsia Mons Elongated Cloud doesn’t just come, it lingers for a while and then dissipates. It forms and fades for several hours each local morning, then returns the next day. This makes the strange cloud difficult to study from orbit around the Red Planet.
But Mars Express is uniquely qualified to do so. He wears an instrument called the Visual monitoring camerawhich can shoot in one frame an unusually wide stream from the planet. And the spacecraft’s orbit rises to put Arsia Mons in sight in the morning when the cloud is visible.
“The size of this huge cloud cannot be seen if your camera has only a narrow field of view or if you observe only in the afternoon,” said Eleni Ravanis, a graduate trainee in the camera’s visual surveillance team. “Fortunately for Mars Express, the spacecraft’s highly elliptical orbit, combined with the VMC’s wide field of view, allows us to take pictures covering a wide area of the planet in the early morning. That means we can capture it!”
Scientists last seen Arsia Mons tail-like cloud in September and October 2018. At that time and again, the days are the shortest in the year in the northern hemisphere of the Red Planet and the longest in the year in the southern hemisphere. Arsia Mons itself is located just south of the Martian equator and stretches at an altitude of about 12 miles (20 km).
Scientists hope that by continuing to study the strange cloud, they will be able to begin to understand how long it has appeared and why it appears only in the morning.
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