Portal:Astronomy/Picture/Week 19 2006
Appearance
The Coalsack Nebula is a dark nebula in the constellation of Crux Australis. Dark nebulae consist of cold dense clouds of gas and dust, which are only seen because they obscure visible light from more distant objects. Dark nebulae are often the location of star formation, which can be revealed within them by observations at infrared and radio wavelengths, which are much less affected by absorption and scattering by interstellar material