Convection Could Produce Pluto's Polygons, Researchers Say

Pluto has been discovered to possess an unusual polygonal terrain by NASA's New Horizons mission to the planet's system. The planet is covered with large deposits of nitrogen ice in the form of polygons that are thin from the edges and thick from the middle.

Now, a team of researchers from the Purdue University has proposed that the polygons seen on the surface of the planet could be actually the Rayleigh-Bénard convection cells. The complete details of the study conducted by the researchers are scheduled to be published in the journal Nature.

According to the researchers, the polygons seen on the surface of Pluto could be a roiling sea of volatile nitrogen ice. This explains the appearance of the Sputnik Planum region on the surface of the dwarf planet.

Although the surface of the dwarf planet may seem like very cold water ice, but within the Sputnik Planum region, the icy surface drops itself into a basin containing nitrogen ice. While both water and ice appear solid on the surface of the planet, nitrogen ice has low viscosity and structural weakness that deforms it and gives it fluidity. On the other hand, the water ice is hard with very high viscosity, enough to form hard mountains.

The researchers further say that within the pool of nitrogen ice, the mountains formed by the water ice have collected at the edges of the polygon. The pattern of their collection indicated that they have floated on the surface of the planet along the convection current.

In case this is true, the researchers say that they can calculate the depth of the nitrogen pool using the known facts about the width to depth ration for convection cells. Another team led by researcher William McKinnon confirmed that convection cells could be the most viable reason behind the polygons.