interstellar medium(redirected from Interstellar matter)
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Related to Interstellar matter: Interstellar dust
Material, mostly hydrogen gas, other gases, and dust, occupying the space between the stars and providing the raw material for the formation of new stars.
(Astronomy) the matter occurring between the stars of our Galaxy, largely in the spiral arms, and consisting mainly of huge clouds of ionized, neutral, or molecular hydrogen. Abbreviation: ISM