Mordor Macula /ˈmɔːrdɔːr ˈmækjʊlə/ is the informal name for a large dark area about 475 km in diameter near the north pole of Charon, Pluto's largest moon.

Mordor Macula's dark "core" is roughly 375 kilometers in diameter, though a surrounding lighter halo extends further into the highlands of Oz Terra, beginning to appear north of 45°N and trending darker with increasing latitude.

In the direction of the 90°W meridian by contrast, Mordor Macula's terrain gently slopes downwards to ~2 km below Charon's mean elevation before encountering the McCaffrey Dorsum.

Pluto's dark equatorial terrain is covered in deposits of tholins, a generic term for a tar-like mixture of radiation-processed organic compounds.

A leading hypothesis is that nitrogen and methane escape from Pluto's atmosphere and are then deposited into the cold poles of Charon, where scattered ultraviolet light then transforms the molecules into tholins, a generic term for a tar-like organic slurry.

[5] Observations of other Kuiper belt objects (KBOs) show similar features as Mordor Macula, making the atmospheric transfer model less likely.

After a long period of time, solar radiation irradiated the trapped methane ice and produced tholins, creating the dark deposits observed today.