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:
“Perhaps I stand now on the eve of a new life, shall watch the sun rise and disappear behind a black cloud extending out into a grey sky cover. I shall not be deceived by its glory. If it is to be so, there is work and the influence that work brings, but not happiness. Am I strong enough to face that?”
—Beatrice Potter Webb (1858–1943)