Charon’s Blood-Red Spot Of Mordor: Mystery Of Dark Patch On Pluto's Largest Moon Solved

It's been a long while since NASA's new Horizon's space probe left Pluto behind, but scientists are still trying to unveil the mystery of this dwarf planet along with its satellites. The latest research is now focusing on the dark red spot of Charon, the dwarf planet's largest moon.

Orbiting the frozen world in the darkest edges of our solar system, the blood-red north pole of Charon appeared so menacing that astronomers nicknamed it 'Mordor' after the shadowy lands home to the evil Sauron in Lord of the Rings. A careful study of images that was beamed back by the New Horizon's space probe may now have uncovered the causes of the dark red patch on the cold planet's moon. Scientists believe the area has been created by methane gas trapped on the surface, reports dailymail.

Will Grundy of the Lowell Observatory and his colleagues had been analyzing detailed images of the red spot when they made some strange discoveries. The north pole is found to be covered in a chemical, 'Tholin', which gives both the spot as well as Pluto its characteristic red color.

Dr Grundy told IFLScience in an interview, "This is the very first example when a planet's escaping atmosphere has affected its moon's surface. It's as if Pluto is a graffiti artist who's spray painting Charon's poles using its escaping atmosphere." In a recent paper, published in the Nature, the team suggests the main reason for this red spot is Pluto's extremely cold temperatures. The methane gets trapped during its cold winter and just as spring comes; it gets converted into the red-colored chemicals.

Tholin is formed by organic compounds exposed to U.V. radiation. As methane is too volatile to get attached to the moon and be converted on its own, the seasonal conditions on Pluto make the difference. The team had also previously suggested that methane from Pluto's atmosphere gets trapped in the moon's north pole and slowly gets converted into tholin. This recent study has provided an accurate model for this conversion.

The research though also suggests that this particular spot is not the only one. There have been indications that Charon's south pole has a similar feature. The other smaller sized moons of Pluto, like Nix, may also have these red spots. Obviously as the smaller satellites sent there are less massive, the process carried on is mostly less efficient, the researchers conclude.