The distance light travels in one year in a vacuum: approximately 9.461 trillion km. Used to express astronomical distances outside the solar system. Alpha Centauri, the nearest star system, is about 4.37 light-years away.
A unit of distance equal to about 3.26 light-years (30.9 trillion km). Derived from parallax of one arcsecond. Professio...
A unit of measurement equal to the average distance between Earth and the Sun, approximately 149.6 million kilometers (9...
The speed light travels in vacuum: approximately 299,792 km/s. According to special relativity, this is the universal sp...
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