interstellar medium

noun

1. 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 ISM

interstellar medium

/ ĭn′tər-stĕl′ər /

1. 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. Nebulae are the most distinct areas of the interstellar medium; they appear when the clouds of gas and dust cluster due to interaction with nearby stars or star remnants.

Example Sentences

This allowed scientists to map everything from dust in the interstellar medium to the largest scale of structure in the universe, galaxy clusters.

From Los Angeles Times

“It is surprisingly difficult to observe the interstellar medium that is just outside of our heliosphere.”

From Science Magazine

Astrospheres, stellar analogues of the heliosphere that surrounds our solar system, are very hot plasma bubbles blown by stellar winds into the interstellar medium, a space filled with gas and dust.

From Science Daily

Under the influence of gravity, material from the interstellar medium falls inward onto the star and the disk, where it serves as the raw material for planets and their precursors.

From Science Daily

This material plays an important role in the interstellar medium and the formation of stars and planets, but its origin is a mystery.

From Science Daily