Mordor Macula is located at Charon. A large dark area about 475 km in diameter near the north pole of Charon, Pluto's largest moon. It is named after the shadow lands in J.R.R. Tolkien's The Lord of the Rings. The name is not official; the discovery team has been using the name informally and may submit it to the IAU. It is not currently known what Mordor is. It may be frozen gases captured from Pluto's escaping atmosphere, a large impact basin, or both.