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 |
|---|---|
| Variation |
A term in the mathematical expression for the ecliptic longitude of the Moon which varies with a period of half a synodic month and has a maximum value of 40 arc minutes. It arises because the Sun’s gravitational attraction on the Moon varies during the course of a synodic month, being greatest at new Moon and least at full Moon.
|