Mars Express sees fascinating ice-related features in Utopia Planitia

Utopia Planitia, a large lava plain in the northern hemisphere of Mars, is about 3,300 km (2,051 miles) in diameter – just under twice the north-south size of the Sahara Desert on Earth.

This image shows Utopia Planitia, a plain that fills one of the three major basins of Mars’ northern hemisphere. Image credit: ESA / DLR / FU Berlin / CC BY-SA 3.0 IGO.

The new image, captured by the High-Resolution Stereo Camera (HRSC) on ESA’s Mars Express spacecraft, shows a slice of Utopia Planitia, the plain that fills this ancient basin.

This plain is believed to have formed when Utopia Planitia was filled with a mixture of sediments, lava, and volatile substances, all transported across the Martian surface by water, wind, or other processes.

“Utopia Planitia is a fascinating region rich in ice; ice has been spotted both on the surface and just below, and at greater depths,” ESA researchers said.

“Visible at the top and bottom of the scene are large smooth surfaces called ‘covered deposits’.”

“These are thick layers of ice- and dust-rich material that smoothed the surface and were probably deposited as snow when Mars’ axis of rotation was much more tilted than it is today. .”

“Moving back to the center of the image, the two largest impact craters visible here are surrounded by mounds of double-layered material.”

“A similar layered appearance is also seen in deposits that have accumulated in the craters themselves and in the thick rims of the craters.”

The second-largest crater in the HRSC image features a texture known as brain terrain, where material has warped and deformed in a concentric pattern that resembles the intricate patterns and ridges found on the surface of the human brain.

“Brain terrain is associated with icy material found near the boundary between Mars’ northern plains and its southern highlands, a ‘dichotomy’ located to the south/southwest (upper right) of this scene”, said the scientists.

“Just below the brain-textured crater is a particularly dark region, created when the ice-rich ground contracted and cracked at low temperatures.”

“This formed polygonal patterns and fractures which then captured the dark dust blown onto Mars by the wind, leading to the dark appearance seen here.”

“Also, the scalloped depressions are ubiquitous in this image. These have circular to elliptical shapes, depths of several tens of meters and sizes varying from tens to thousands of meters in diameter.

“These features are the result of ground ice melting or turning into gas, which then causes the surface to weaken and collapse. On closer inspection, layered deposits can also be seen in and around these scalloped depressions.