The HiRISE (High Resolution Imaging Science Experiment) camera on the Mars Reconnaissance Orbiter has seen many polygon shapes over the years since 2006 when it orbited Mars. (NASA / JPL / UArizona) Above: Polygonal dunes on Mars, as seen by the HiRISE camera on the Mars Reconnaissance Orbiter. The HiRISE team says that both water and carbon dioxide in the solid form of dry ice play an important role in sculpting the surface of Mars over large latitudes. The ice of frozen water on the ground divides the soil into polygonal shapes. Then the dry ice that sublimates just below the surface when the ground warms up in the spring creates even more erosion, creating channels around the boundaries of the polygons. (NASA / JPL-Caltech / UArizona) Above: Spring fans and polygons on Mars, as seen by the HiRISE camera on the Mars Reconnaissance Orbiter. The polygons are formed for many years as the ice near the surface shrinks and expands seasonally. But this area covered by a polygon shows even greater spring activity, as evidenced by the blue fan-shaped features. Scientists say that the layer of translucent dry ice that covers the surface develops air ducts that allow gas to escape. “The gas carries fine particles of material from the surface further eroding the channels,” the team wrote on the HiRISE website. “Particles fall to the surface in dark fan-shaped deposits. Sometimes dark particles sink into the dry ice, leaving light marks where the fans were originally placed. Often the hole closes and then reopens, so we see two or more fans.” which comes from the same point but is oriented in different directions as the wind changes “. (NASA / JPL) Above: Detailed image of large-scale crater floor polygons, caused by the drying process, with smaller polygons caused by thermal shrinkage inside. The central polygon has a diameter of 160 meters, the smaller ones range from 10 to 15 meters in width and the cracks have a diameter of 5 -10 meters. Scientists are studying the soil with a polygonal pattern on Mars, because these features help them understand the recent and previous distribution of ice in the shallow subsoil, as well as provide clues to climatic conditions. And Mars is not the only place with polygons. Polygons can be found in the Arctic and Antarctic Earth regions, and the 2015 flight from the New Horizons spacecraft revealed polygons to Pluto as well. (NASA / JHUAPL / SWRI) Above: Polygons seen on Pluto. In the center left of Pluto’s huge heart-shaped element – unofficially called “Tombaugh Regio” – is a vast crater-free plain that appears to be no more than 100 million years old and is probably still formed by geological processes. This icy region is located north of Pluto’s icy mountains and has been unofficially named Sputnik Planum (Sputnik Plain), after Earth’s first artificial satellite. The surface appears to be divided into polygon-shaped sections enclosed by narrow troughs. Features that appear to be embankment groups and small pit fields are also visible. This image was obtained by the Long Range Reconnaissance Imager (LORRI) on July 14 from a distance of 48,000 miles (77,000 kilometers). Features as small as half a mile (1 km) are visible. The blocked display of some features is due to image compression. This article was originally published by Universe Today. Read the original article.
