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 |
|---|---|
| D Layer |
A region of the Earth’s ionosphere at heights between about 50 and 90 kilometres 30 and 55 miles. The lower D layer, between heights of 50 and 70 kilometres, is also known as the C layer.
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