Like all scientists, astronomers use tools to make measurements about the things they study. Astronomers use very powerful telescopes that work just like the smaller telescopes that amateur astronomers use, to look at the objects they study in space. They also use huge emitters and receivers to send and receive radio signals from space. These radio signals can tell the astronomers how far away a planet or a star is, how big it is, and, if it's moving, how fast it's moving. Radio waves and telescopes are only a couple of examples of the many instruments astronomers use to observe and study space.
Space holds many unknowns.
It is a place humans can visit, but we are not yet able to live there. The study of astronomy can help us learn about the many mysteries of the universe. Produced by Galactics . Last updated on 14 August 1998.