The presence of methane ice on Pluto's "halo" craters as seen in NASA's newest pictures has caused confusion to astronomers.
More specifically, the agency's New Horizons spacecraft issued a new batch of images on April 21, which featured one-of-a-kind craters in the west area of Pluto.
What made the photos more interesting is that the bright spots are composed of methane ice.
"Within Pluto's informally named Vega Terra region is a field of eye-catching craters that looks like a cluster of bright halos scattered across a dark landscape," writes NASA.
New Horizons was at the far west area of the planet when it took the photos. The photos were taken from 28,000 miles and 106,700 miles from the planet, exactly on July 14, 2015.
All Eyes On The Halo Craters
One of the photos showed numerous craters with halos, with the largest approximately measuring about 30 miles (50 kilometers) across. The said area has dark floors and apparent terrains, making their bright walls and rims stand out, creating the halo effect.
The photos also include one that seems to connect the bright haloes and the methane ice. The terrain and floors look as if they contain water ice.
The reason why the bright methane ice is situated on these walls and rims is a puzzling mystery. What's even more intriguing for the scientists is the fact that this effect is not present all throughout the planet.
Methane Ice
Analysis from NASA confirmed that the bright areas were made up of both methane and water.
In the past, experts have already noted that methane ice does not settle anywhere in the rims and walls of craters on the planet. This is the reason why the new photos have created such tremendous mystery.
In March, rumors of Pluto having snow emerged following the release of photos showing "snowcapped mountains," which were very apparent against the dark background of Pluto's Cthulhu.
The New Horizons team, however, was quick to say that the snow seen on Pluto is very different from what humans have on Earth.
The main difference is that the snow on Pluto is made of methane that condensed into ice. This means that methane ice is like water in Pluto such that it turns into frost in high altitudes.
