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 |
|---|---|
| Julian Year |
A period of 365.25 days. Since 1984, standard epochs have been defined in terms of the Julian years, whereas previously the Besselian year was used.
|