ESA has published a new image taken by the Mars Express mission. It shows the eastern part of the Arcadia Planitia, a region that is often referred to as the leading candidate for the site of the first manned landing on Mars.
Palette of Martian colors
Arcadia Planitia is located northwest of the giant volcanic region of Tharsis, home to the tallest volcanoes in the entire Solar System. It has a relatively flat relief and is mostly covered by old solidified lava flows that are no more than three billion years old.
At first glance, the image obtained by Mars Express may appear slightly blurred. However, this is not the case. The air here is filled with tiny particles that rise and are carried away by passing winds, creating a kind of haze that gives the effect of blurring. Wind plays an important role on Mars, constantly changing the landscape and transporting sand from one place to another.
This is especially clear here. The upper part of the image, colored red, is covered with streamlined rocky ridges known as yardangs, which have previously been observed by Mars Express. These ridges were carved out of surface rocks by sand and dust lifted by Martian winds. They resemble small clusters of parallel scratches scattered across the surface.
The yardangs are located next to a much larger curved arc that runs across the frame and divides the image roughly in half. On the other side, the terrain is darker. The variety of colors observed here is probably due to a mixture of different materials and the properties of the sand grains and the way they accumulate on Mars. Reddish soil is rich in iron, while darker soil is rich in silicates.
Dust whirlwinds
Although Mars is a world very different from ours, we often observe similar phenomena there. One example is dust whirlwinds. On Mars, tornadoes regularly sweep across the planet’s wide plains. They form when the surface heats up during the day and heats the layers of air directly above it. They rise, creating whirlwinds that carry away dust and sand.
Although Martian dust whirlwinds are similar to those on Earth in many ways, they are much larger due to more extreme temperature fluctuations. They can move at speeds of up to 45 m/s and reach heights of up to 8 km, which is comparable to Mount Everest. Small tornadoes last only a few minutes, while larger ones can exist for over an hour.
Possible ice deposits
Finally, in the lower right corner of the frame, there is a large impact crater with a diameter of about 15 km. The crater is surrounded by layered bulges of material extending from the impact zone — a clear indication that the ground contained a significant amount of water ice at the time of impact. Since the crater is virtually undamaged and has not undergone significant erosion, the collision probably occurred relatively recently in geological terms.
The possible presence of water on Mars has always been a subject of great interest. Climate models suggest that in the recent past, water ice could have extended as far as the planet’s mid-latitudes, rather than being confined to the poles as it is today. As a result, its deposits can still be found in several of these regions today, as it is located quite close to the surface (at a depth of only one meter or even less).
All this makes Arcadia Planitia a promising location for future manned missions and the construction of the first Martian settlement. At least, it is currently the leading candidate at SpaceX.
According to ESA
