interstellar medium

1 of 1noun

/ˌɪntərˈstɛlər ˈmidiəm/

1

the matter and radiation that exists in the space between stars within a galaxy

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The interstellar medium is made up of gas, dust, and cosmic rays.
Cosmic rays interact with the interstellar medium, producing radiation.
Space probes collect data on the composition of the interstellar medium.
The interstellar medium absorbs and scatters starlight.
Astronomers study the interstellar medium to understand cosmic evolution.