Strange Dunes on Mars

NASA's Mars Reconnaissance Orbiter captured some fascinating images.

Planetary scientists have spotted near-perfectly circular sand dunes on the surface of Mars, which is unusual considering sand dunes across the Red Planet come in a wealth of shapes and sizes.

The image was taken on November 22, 2022, using the High-Resolution Imaging Experiment camera that orbits Mars on the Mars Reconnaissance Orbiter spacecraft.

It shows the slight asymmetry in the sand dunes, with their steep sides oriented towards the south, indicating that the sands are blown southwards, though Martian winds may be variable.

The collection of images being used to monitor how frost recedes and melts on the Martian surface as the Red Planet reaches the end of its winter season.

The high-resolution camera has been orbiting the Red Planet since the MRO reached Mars in 2006, conducting the first dedicated survey of the planet's sand dunes.

By collecting repeated observations of sand dunes over the Martian year, which lasts 687 Earth days, planetary scientists have been able to monitor how fast the dunes move.

This has revealed that sand dunes from the equator to the poles are advancing at rates of up to 3.3 feet, or 1 meter, per Martian year.

The camera has recorded a variety of Martian sand dunes with an impressive range of both sizes and shapes, revealing a great deal about weather conditions on the Red Planet.

These images can help scientists determine the kind of fracture mechanics that occur in so-called viscous flow features found at the bases of slopes on Mars.