7 Things We've Learnt About Pluto Since New Horizons
6. Charon Has Been Surprising
Pluto's largest moon, Charon, has proved to be just as interesting as its host. There is actually debate as to whether Charon is a moon at all, or whether it is another dwarf planet, locked in a binary orbit with Pluto. The moon doesn't strictly orbit Pluto as the barycentre (the centre of orbit) lies beyond the dwarf planet's surface - the two bodies actually orbit a common point, as can be seen in this animation. Charon's surface is slashed across by an enormous canyon that encircles the entire planet, making it four times bigger than the Grand Canyon in the United States. The large dark area at the northern polar region has been informally named "Mordor" by those jokers at NASA. To be fair, it is pretty difficult to walk into. One of the most puzzling features of the moon's surface is the "mountain in a moat". This large mountain surrounded by a circular ditch looks simple enough, but the scientists have literally no idea what it is or what could have caused it. Charon, with its canyons, impossible mountains and signs of geological activity, has turned out to be an unexpected highlight of the flyby. New Horizons team member, Bonnie Buratti has said To tell you the truth, Charon looks more like I would have expected Pluto to look. Take a virtual flyby of the supermoon in the video below. https://www.youtube.com/watch?v=lrMBzJcvtt0
