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AsteriaStar
Interstellar environment

The Diffuse Interstellar Medium

The thin, warm, mostly atomic gas that fills the space between the stars, laced with dust that reddens the light passing through it. Even here, exposed to starlight, the first simple molecules form — the beginning of cosmic chemistry.

Across astrochemistry

Knowledge connections

Sources

The primary and reference sources this topic draws on.

  • NASANational Aeronautics and Space Administration

    Mission data, planetary science, space telescopes, and public-domain imagery.

    Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.