What does interstellar mean?
Interstellar is an adjective describing anything located, occurring, or existing between stars. It is especially common in astronomy, where interstellar space contains the gas, dust, radiation, magnetic fields, and other matter between stellar systems. The term also appears in discussions of interstellar travel, comets, meteors, and signals passing through the space around nearby stars. In science fiction, it evokes journeys across vast cosmic distances and the difficulties of communication or movement on that scale. Interstellar should not be confused with interplanetary, which refers specifically to the region between planets within a solar system. The word combines the prefix inter-, meaning “between,” with stellar, meaning “relating to stars,” and is used in both formal scientific writing and popular descriptions of space exploration.
adjectiveExisting, occurring, or taking place between stars. It may describe objects, regions, matter, or journeys in the space separating stars.
- Located, occurring, or existing between stars.
- Involving travel or communication across the distances separating stars.
"The observatory detected an unusual signal from deep within interstellar space."
"Scientists study interstellar dust to understand how stars form."
"The film imagines a crew making an interstellar journey beyond the solar system."
The universe may look empty, but interstellar space is filled with the gas, dust, magnetic fields, and radiation that shape the stars within it.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does interstellar come from?
Interstellar was formed in English from the prefix inter-, meaning “between,” and the adjective stellar, meaning “of or relating to stars.” Stellar comes through Latin stellaris, derived from stella, “star,” from Latin, which in turn continues the ancient Greek word for star. The compound interstellar is used for the regions and phenomena located between stars, as distinct from those within a single star or planetary system.
How interstellar is actually used
The term is standard in astronomy and science fiction. In astronomy, it is distinct from interplanetary, which concerns the space between planets in a solar system.
Easily confused with interstellar
Interstellar means between or beyond stars, whereas interplanetary means between planets, especially within a solar system.
Interstellar refers to the space between stars, while intragalactic refers to a region within a galaxy.