There's something weird on Pluto that's been bugging astronomers. NASA' s New Horizons spacecraft recently revealed stunning images of Pluto with some perplexing "halos."

According to Cosmos, the images were captured by Horizon during a close encounter with the dwarf planet in July. The images, which were then sent to NASA scientists, showed a region on Pluto's surface peppered with small halo-like formations, which are, in fact, craters. These craters go as large as 50 kilometers and have bright walls and rims.

What stunned NASA scientists is the fact that the region where these craters were found is composed of methane ice that has settled on Pluto's surface. This occurrence is special to the region as it does not happen to other parts of Pluto.

NASA reports that this region is called the Vega Terra region, located on the far west hemisphere of Pluto. Based on the images, the icy craters look like halos because of the contrast of bright methane ice to the dark atmosphere. NASA also said that in between the craters are signs that water was once present in this area.

Previously, another strange image of an "icy spider" was captured by NASA on Pluto's surface. Tagged as "icy spider," the feature is, in fact, a geological feature on the dwarf planet surface composed of six fractures that converge at one point, according to a separate report by NASA.

The image of Pluto's strange craters was captured by New Horizons' Ralph/Linear Etalon Imaging Spectral Array (LEISA). The captured photo showed hues of purple and blue to indicate the methane ice composition of the craters.

Gizmodo notes that New Horizons has provided NASA with three years of data about solar particles in the outer space. Besides Pluto, New Horizons has been studying a lot about structures further from Earth. Scientists hope that these findings might help them determine the boundary between our solar system and what lies beyond.