Coalsack Nebula

5 ° x 7 °

500-600 Lj

The Coal Sack is one of the most well-known dark clouds in the sky and next Horsehead Nebula, Cone Nebula and other one of the few objects of this type with a proper name. The Coal Sack is in the middle of the southern Milky Way between the constellations Crux ( the Southern Cross ), the Centaur surrounding him and the fly (Musca ). He is 500-600 light years away, forming a conspicuous " hole" in the surrounding, very star- rich area. Known objects in " binocular distance " are the Eta Carinae nebula and open cluster NGC 4755, the John Herschel called the " jewel box ".

The Aborigines in Australia to know the number of dark clouds from the constellation Shield in the north down to the sack of coal as " the Emu " - with the carbon bag for a head.

The astronomer Kaveli Mattila could find in 1970 that the dark mist is not completely black, but very dim ( about 10 % of the light behind the Milky Way ). This is caused by the light reflection of the underlying, darkened star.

Trivia

The fog also plays a central role in the novel The splinter in the eye of God by Larry Niven.