The landscape of the border between the two regions was published by ESA last week
The Mars Express orbiter, which has orbited the red planet for more than two decades, has captured a stunning image of Mars' north polar region.
North polar region of Mars — an attractive and unusual place even by the standards of this unusual planet. In this region, the dust covering the surface of Mars mixes with water ice. Layers upon layers of dust and ice lie miles deep, covering an area the size of France.
For most of the Martian year, this region is buried under a cap of frozen carbon dioxide. But when Martian summer arrives, dry ice escapes into the planet's atmosphere. And it was in the middle of summer that the orbiter «Mars Express» captured a small fragment of the northern polar landscape.
Photo taken on April 14, 2023, just last week, shows the border between two different regions — Olympia Planum and Planum Boreum. Olympia Planum — it is a vast area with wide sand dunes. On the other side of the border is Planum Boreum, which includes the north pole of Mars, which is out of frame to the right of the image. The surface of Planum Boreum is smooth, indicating its youth and the absence of destructive erosion and meteorite impacts. It is likely that Planum Boreum is renewed every year with the coming and going of winter ice.
Crescent-shaped rocks stretch between the borders, the largest of which is about 20 kilometers wide. These rocks form spiral depressions that span the entire north pole of Mars. Their formation is associated with the action of winds on the surface of the planet.
Mars Express has been in orbit around Mars for more than two decades, since December 25, 2003. The spacecraft not only took numerous high-resolution images of the surface of Mars, but also helped in studying the Martian atmosphere and exploring the surface of the planet.