A light-year (Japanese: 光年) is a measurement of length equal to the distance travelled by light in a vacuum over the course of an Earth year, and is equivalent to about 9.4 trillion (9,460,000,000,000) kilometres.

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v•d•e Astronomy topics
General phenomena Asteroid (category) • Black hole • Planet (category) • Star (category) • Starzone (category)
Other Galaxy • Light-year • Navigation corridors • Orion Arm • Sagittarius Arm