Interstellar cloud is the generic name given to an accumulation of gas, plasma and dust in our and other galaxies. Put differently, an interstellar cloud is a denser-than-average region of the interstellar medium. Depending on the density, size and temperature of a given cloud, the hydrogen in it can be neutral (H I regions), ionized (H II regions) (i.e. a plasma), or molecular (molecular clouds). Neutral and ionized clouds are sometimes also called diffuse clouds, while molecular clouds are sometimes also referred to as dense clouds.
Read more about Interstellar Cloud: Chemical Compositions, Unexpected Chemicals Detected in Interstellar Clouds, High-velocity Cloud
Famous quotes containing the word cloud:
“The cloud was so dark that it needed all the bright lights that could be turned upon it. But for four years there was a contagion of nobility in the land, and the best blood North and South poured itself out a libation to propitiate the deities of Truth and Justice. The great sin of slavery was washed out, but at what a cost!”
—M. E. W. Sherwood (1826–1903)