Molecular cloud
A molecular cloud is a kind of cloud in space. It has enough density and size so that molecules can form, usually molecules of hydrogen (H2). Molecular hydrogen is not easy to find. Instead astronomers use infrared telescopes and radio telescopes to look for CO (carbon monoxide). This lets them find the hydrogen molecules that are also there.
Molecular Cloud Media
Molecular cloud Barnard 68, about 500 ly distant and 0.5 ly in diameter
Circinus molecular cloud has a mass around 250,000 times that of the Sun.
Within a few million years the light from bright stars will have boiled away this molecular cloud of gas and dust. The cloud has broken off from the Carina Nebula. Newly formed stars are visible nearby, their images reddened by blue light being preferentially scattered by the pervasive dust. This image spans about two light-years and was taken by the Hubble Space Telescope in 1999.
Part of the Taurus molecular cloud
Distribution of molecular gas in 30 merging galaxies.
Young stars in and around molecular cloud Cepheus B. Radiation from one bright, massive star is destroying the cloud (from top to bottom in this image) while simultaneously triggering the formation of new stars.
The Serpens South star cluster is embedded in a filamentary molecular cloud, seen as a dark ribbon passing vertically through the cluster. This cloud has served as a testbed for studies of molecular cloud stability.
The Milky Way as seen by Gaia, with prominent dark nebulae many of which are molecular cloud complex (labeled in white), as well as prominent star clouds (labeled in black).
