Just from orbit, the Martian landscape can look like lacy honeycombs or spider webs. But the unusual polygon-shaped features are not created by Martian bees or spiders. In fact, they were formed by a continuous process of seasonal change.
The HiRISE – High Resolution Imaging Science Experiment – camera on the Mars Reconnaissance Orbiter has seen a lot of shapes in the years since 2006, when it entered Mars’ orbit.
The HiRISE science team says that both water and carbon dioxide in the solid form of dry ice play a major role in sculpting the surface of Mars at high latitudes, indicates Science Alert.
Frozen water in the soil divides the earth into polygonal shapes. Then the dry ice that sublimates from below the soil surface when the ground warms in the spring creates even more erosion, creating channels around the boundaries of the polygons.
Polygons are formed over the years
Polygons form over many years as near-surface ice contracts and expands seasonally.
But this polygon-shaped covered region shows even more activity in the spring, highlighted by blue fan-shaped features. Scientists say the layer of translucent dry ice covering the surface is developing vents that allow gas to escape to the surface.
“The gas carries fine particles of material from the surface, further eroding the channels,” the team wrote on the HiRISE website. “The particles fall to the surface in dark fan-shaped deposits. Sometimes the dark particles sink into the dry ice, leaving bright trails where the fans were originally deposited. Often the vent closes, then opens again, but the orientation varies with wind direction.”
Patterns on Mars, a topic of interest for scientists
Scientists study polygon-patterned terrain on Mars because these features help them understand the recent and past distribution of ice in the shallow basement, as well as provide clues about climate conditions.
But Mars isn’t the only place with polygons. Polygons can be found in the Arctic and Antarctic regions of Earth, and the 2015 flyby of the New Horizons spacecraft revealed polygons on Pluto as well.
In the center-left area of Pluto’s vast heart-shaped surface—informally called the “Tombaugh Regio”—is a vast, crater-free plain that appears to be no more than 100 million years old and is possibly still being shaped of geological processes.
What lies north of Pluto’s icy mountains?
This icy region lies north of Pluto’s icy mountains and has been informally named the Sputnik Plain, after Earth’s first artificial satellite. The surface appears to be divided into polygon-shaped segments that are surrounded by narrow troughs.
Also visible are features that appear to be groups of mounds and fields of small pits. This image was acquired by the Long Range Reconnaissance Imager – LORRI on July 14 from a distance of 77,000 kilometers.