Coalsack Nebula

The Coalsack Nebula, also known as the Southern Coalsack or simply the Coalsack, is a dark nebula. It can be seen without a telescope as a dark patch that blocks part of the Milky Way. This dark area appears east of Acrux (Alpha Crucis), the brightest star, in the constellation of Crux.

Dark nebulae like the Coalsack are clouds of dust and gas in space. They block light from the stars behind them, which is why they look dark in the night sky. The Coalsack Nebula is one of the most easily recognizable dark nebulae because it is visible to the naked eye.

The Coalsack is part of the Milky Way, our home galaxy, and it helps astronomers study how stars form and how space is filled with different kinds of matter. Looking at the Coalsack can be a fun way to explore the night sky and learn about the different things that exist far above us.

General information

Historically, any dark cloud in the night sky was called a coalsack. The Coalsack Nebula was named in 1899 by Richard Hinckley Allen, who called it alongside the Northern Coalsack Nebula.

The Coalsack Nebula covers nearly 7° by 5° and extends into the neighboring constellations Centaurus and Musca. In Australian Aboriginal astronomy, the Coalsack forms the head of the emu in the sky in several Aboriginal cultures. In Inca astronomy, this nebula was called Yutu, after a partridge-like South American bird, or Tinamou.

In popular culture

The Coalsack Nebula has appeared in stories and books. In Kenji Miyazawa’s tale Night on the Galactic Railroad, the Coalsack represents a mysterious, empty space that a character sees when his friend travels to an afterlife.

The Coalsack Nebula also plays an important role in science fiction books by Jerry Pournelle and Larry Niven. In stories like The Mote in God's Eye, the Coalsack helps set the scene for a faraway planet called New Caledonia.