Space exploration began with the launch of Sputnik and Astrophysics was born as the application of physics to the phenomena observed by Astronomy, which etymologically means laws of the stars.
There are 2759 entries in this glossary.| Term | Definition |
|---|---|
| Radian |
A unit in which angles are measured. It is the angle subtended by an arc of a circle that has the same length as its radius. Thus, 2π radians are equivalent to 360° and one radian is approximately 57.30°.
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