Astronomers using the Kepler telescope have detected the darkest known planet. It has a faint, reddish glow. Its surface temperature is about 1800 degrees C., which makes it too hot to form methane clouds that would reflect more light. Its chemistry is partially known. It is
…a Jupiter-sized exoplanet some 750 light-years away that is so black that it reflects just one percent of the light that reaches it. TrES-2b is so black that it’s darker than coal, or any other planet or moon that we’ve yet discovered. It’s less reflective than black acrylic paint….. TrES-2b’s atmosphere is made up of things like vaporized sodium, potassium, and titanium oxide–things that actually compound the problem by absorbing heat. But even these don’t fully explain the planet’s extreme blackness, which is still puzzling astronomers. There’s some kind of strange chemistry going on out there that even Kepler can’t see.