2024-02-28 16:46:37
This image from ESA’s Mars Express spacecraft shows the terrain around the north pole of Mars. Capture the region where vast, rolling sand dunes meet the layers upon layers of dusty ice that cover the planet’s pole. Credits: ESA/DLR/FU Berlin
ESA’s Mars Express probe has captured an intriguing view near the north pole of Mars, where vast sand dunes meet the numerous layers of dusty ice that cover the planet’s pole.
The terrain surrounding the north pole of Mars, known as Planum Boreum, is fascinating. The pole itself is covered in layers and layers of fine dust and water ice; These accumulate several kilometers thick and extend over regarding 1,000 km (approximately the width of France).
While most of this material is not visible here, the beginnings of Planum Boreum can be seen to the right of the image, with some subtle wrinkles showing where layers of material begin to build up. The terrain has also been built up more markedly in steps, as seen more clearly in the topographical view of this region below. The lower altitude regions are blue/green and the higher ones are red/white/brown.
This color-coded topographic image shows the region surrounding the north pole of Mars. It was created from data collected by ESA’s Mars Express on April 14, 2023 and is based on a digital terrain model of the region, from which the topography of the landscape can be derived. The lower parts of the surface are shown in blues and purples, while higher altitude regions are shown in whites and reds, as indicated by the scale at the top right. North is to the right. The ground resolution is approximately 21 m/pixel and the image is centered at regarding 231°E/84°N. Credits: ESA/DLR/FU Berlin
These layers formed as a mixture of dust, water ice and frost that settled on the Martian soil over time. Each layer contains valuable information regarding the history of Mars and tells the story of how the planet’s climate has changed over the past few million years.
In the Martian winter, the layers are covered by a thin layer of dry ice (carbon dioxide ice) a couple of meters thick. This layer completely disappears into the atmosphere every Martian summer.
This image comes from the Mars Express High Resolution Stereo Camera (HRSC). Two steep banks, or escarpments, vertically cut the image. These mark the boundary between the aforementioned layered deposits (which extend out of the image towards the pole, on the right) and the vast, expansive dune fields that cover the lower terrain of Olympia Planum (on the left).
Ice Walls
The left side of this image is dominated by a vast, elongated strip of undulating sand dunes, stretching for over 150 km in this image alone. This wrinkled and turbulent appearance contrasts greatly with the smooth, more pristine terrain visible to the right.
This smooth region lacks clear signs of erosion and has avoided being hit by incoming rocks from space, an indicator that the surface is very young and likely rejuvenating each year.
Between these two extremes are two semicircular cliffs, the largest of which is regarding 20 km wide. Within the curves of these cliffs are sand dunes covered in frost. The sheer scale of the cliffs is clear from the dark shadows they cast on the surface: their steep, icy walls rise up to a kilometer high.
These two cliffs are located in the so-called polar trough, a feature created when the wind pushes and wears away the surface. These appear as wavy ridges in the terrain and are common in this region, creating the distinctive spiral-shaped pattern of the polar plateau.
Mars Express has been orbiting the Red Planet since 2003. It is imaging the surface of Mars, mapping its minerals, identifying the composition and circulation of its tenuous atmosphere, probing beneath its crust, and exploring how various phenomena interact in the Martian environment.
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