interstellar

Interstellar is an adjective meaning occurring between stars or situated in the space between star systems. The term derives from the Latin inter (“between”) and astrum (“star”). In astronomy and astrophysics, interstellar is used to describe phenomena and regions outside a single star’s immediate environment, within a galaxy.

Interstellar space refers to the vast expanses separating stars within a galaxy. It contains the interstellar medium, a low-density mix of gas (primarily hydrogen) and dust, permeated by cosmic rays and magnetic fields. Though mostly empty, it hosts processes such as star formation in molecular clouds and the propagation of light and radiation across the galaxy. Distances are measured in light-years; the Sun resides in the local interstellar neighborhood, with the nearest neighboring star, Proxima Centauri, about 4.24 light-years away.

Interstellar travel is a theoretical topic in physics and space exploration. It examines propulsion methods, energy requirements, and the timescales of journeys to other star systems. Concepts include conventional chemical, nuclear fission/fusion, antimatter propulsion, and speculative ideas such as laser sails, ion drives, generation ships, or faster-than-light concepts like warp drives, which remain speculative and unproven.

Interstellar as a film: In 2014, Interstellar is a science fiction film directed by Christopher Nolan. Its plot follows a group of astronauts who travel through a wormhole near Saturn in search of a new home for humanity as Earth's environment deteriorates. The film is noted for its scientific consultation, visual effects, and a score by Hans Zimmer; it popularized the term in popular culture but is separate from the scientific concept of interstellar space.