The European Space Agency (ESA) has captured this stunning image of Mars from top to bottom with its Mars Express craft which is currently in orbit around the planet. This slice shows Mars from its north to its south pole, with frozen ice caps on top and bottom and a boundary of rock formations between them. The planet’s northern and southern hemispheres are notably different from each other, with the northern hemisphere having low plains with fewer impact craters and the southern hemisphere being more mountainous and crater-scarred.
Scientists still aren’t sure why the hemispheres are so different. “The split between Mars two hemispheres is known as the martian dichotomy, and remains one of the greatest mysteries about the planet,” ESA scientists said in a statement. “Was it formed due to geological processes within Mars mantle? Did the planets crust once comprise various moving tectonic plates, as we see on Earth, that pushed against one another to form the dichotomy? Could it have been created by one or more colossal past impacts — or by another process entirely?”
The Mars Express is not the only ESA craft photographing the red planet. It also has a companion, the ESA-Roscosmos ExoMars Trace Gas Orbiter (TGO), which arrived at the planet in 2016 and has been measuring factors such as the level of methane in the atmosphere.
The TGO recently captured a beautiful and unusual image of the north polar region of Mars using its Color and Stereo Surface Imaging System (CaSSIS) camera. The ice in the polar regions is covered in a thin layer of carbon dioxide which creates these delicately sculpted dunes. When spring arrives, the carbon dioxide sublimates, turning from ice into vapor. This process begins at the bottom of the dunes and moves upward, which causes gas to become trapped under the ice and sand. When the pressure builds and the ice cracks, the gas pushes the sand outward, resulting in the dark streaks which mottle the dunes on the left of the image below.
The ESA will be sending yet another craft to Mars next year. The ExoMars rover will collect geological information from the surface of the planet and use a drill to collect samples of Martian rock, and is set for launch in July 2020.