molecular cloud

American  

[muh-lek-yuh-ler kloud] / məˈlɛk jə lər ˈklaʊd /

noun

Astronomy.

1. an interstellar cloud of gas and dust composed of hydrogen, helium, and other molecular remnants of a supernova.

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molecular cloud British  

noun

1. a cool dense interstellar region composed of a wide variety of molecules, mainly hydrogen, plus some dust, in which stars are forming

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Etymology

Origin of molecular cloud

First recorded in 1970–75

Example Sentences

See Examples For:

molecular cloud

As parts of these clouds collapse under gravity, they create dense regions known as molecular cloud cores where new stars begin to take shape.

From Science Daily ● Jun. 5, 2026

On the other end of the scale, we have the Orion B molecular cloud complex, a truly enormous site of active star formation that’s over a thousand light-years away and many hundreds of light-years across.

From Scientific American ● Apr. 24, 2023

Protostars are very young stars that are still growing in mass via its parent molecular cloud; such objects may have yet to absorb or expel the remaining gas and dust in their planetary nebulae.

From Salon ● Mar. 15, 2023

This newly released image shows a segment of the Chameleon I molecular cloud, some 630 light years from Earth.

From BBC ● Jan. 24, 2023

The Orion molecular cloud is much larger than the star pattern and is truly an impressive structure.

From Textbooks ● Oct. 13, 2016