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 |
|---|---|
| Fourth Contact |
In an eclipse of the Sun, the point when the Moon’s disc finally moves clear of the Sun’s photosphere. In a lunar eclipse, fourth contact occurs when the Moon leaves the full shadow umbra of the Earth. The term may also be used to describe the similar stage in the progress of a transit or occultation.
|