The New Horizons spacecraft is now close enough to Pluto to allow new views of features on the dwarf planet, and the most recent discovery is craters with a halo effect. NASA tweeted that the large craters “look like a cluster of bright halos scattered across a dark landscape.”
According to NASA, the upper left image shown contains several dozen of these “haloed” craters. The largest, at the bottom right of the black and white frame, measures about 30 miles across. The halo effect is due to the bright rims and walls of the craters, which NASA says may be due to a distribution of methane ice, which shows in the lower left image as purple. The area between craters shows as blue and is thought to be water ice.
It is a mystery to scientists exactly why the bright methane ice settles on the crater walls and rims, and also why the effect does not occur across Pluto.
The images were released by NASA on April 21. The unique craters appear in the Vega Terra region, on the western side of Pluto, in a region that NASA said is far west of the hemisphere New Horizons viewed during last summer’s close approach. The images were from 28,800 miles and 106,700 miles away from the dwarf planet.
Image credit NASA/JHUAPL/SwRI