Planetary scientists have taken a picture of almost perfectly round sand dunes on the surface of Mars. While sand dunes on the Red Planet come in a wide variety of shapes and sizes, such well-defined circles are unusual.
The slight asymmetry of the sand dunes shows that their steep slopes are oriented to the south. The statement states that the University of Arizona, which uses the High Resolution Imaging Experiment (HiRise) camera used to acquire the image. (will open in a new tab) that this indicates that the sands are blowing south, although Martian winds can be variable.
The image was taken on November 22, 2022 at a latitude of 42.505 degrees and a longitude of 67.076 degrees. This is part of a series of images taken by the HiRise camera orbiting Mars on the Mars Reconnaissance Orbiter (MRO) spacecraft.
On the subject: Mars: everything you need to know about the Red Planet
The collection of images is being used to watch the frost recede and melt on the surface of Mars as the Red Planet approaches the end of its winter season. Illustrating this, while this image appears free of frost, a similar image taken earlier of the same sand dunes shows what they looked like when still covered in frost.
The image of the sand dune was taken when the MRO was about 185 miles (300 kilometers) above the surface of Mars. Each image pixel corresponds to 25 centimeters (9.8 inches).
This is just one of 60 places on Mars that HiRise is tracking. The high-resolution camera has been orbiting the Red Planet since MRO reached Mars in 2006 and began conducting the first dedicated survey of the planet’s sand dunes.
Collecting repeated observations of sand dunes over the course of a Martian year (lasting 687 Earth days) has allowed planetary scientists to keep track of how fast the dunes are moving. This showed that sand dunes move from the equator to the poles at a rate of up to 3.3 feet (1 meter) per Martian year.
Round sand dunes on the surface of Mars, covered with frost. (Image credit: NASA/JPL-Caltech/UA, Arizona)
The camera captured many Martian sand dunes with an impressive range of sizes and shapes, which says a lot about the weather patterns on the Red Planet. For example, while exploring the Lyot crater in the northern lowlands of Mars in 2010, HiRise photographed dune fields that showed how local winds channeled through the topology of this 146-mile (236-kilometer) wide complex impact crater.
HiRise is also conducting ongoing research that studies glacial-like formations on Mars and examines the crevasses that punctuate their surface. By collecting repeated observations over time, the images could help scientists determine the type of fracture mechanics that occurs in so-called “viscous flow structures” found at the base of slopes on Mars. It is believed that these deposits were once rich in ice, but according to NASA, the source of this ice is still a mystery. (will open in a new tab)
On December 21, 2010, the main MRO mission ended five years and six months after its launch on August 12, 2005. This new image shows that even 12 years after the completion of this mission, the contribution to science made by the spacecraft and its HiRise camera is far from completion.
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