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 |
|---|---|
| Valhalla |
A large circular feature on Callisto, surrounded by fifteen concentric rings. The radius of the outermost ring is 1,500 kilometres 930 miles. The feature was caused by an impact, but no longer shows any significant relief because of the plastic nature of the crust when the impact occurred. The rings are effectively ripples.
|