9 Grammatical Pitfalls
|radar astronomy |
The scientific study of nearby astronomical objects by reflecting microwaves off the objects and analyzing the echoes. The techniques of radio astronomy can be tailored to answer specific questions, such as the rotation period of the inner planets and the Moon. They have has also been used to test General Relativity, measure distances and features of planets in the solar system, and determine the composition, position, and spin of asteroids.