what is radio telescope?

 When we look at stars and planets through a telescope, we see light waves that they send out. Light is a form of radiation. But stars send out other forms of radiation besides light.

Part of the radiation from stars is sent out as radio waves. Some of these waves can be detected by special radio receivers here on earth.

The radio receivers collect and magnify the radio waves, just as ordinary telescopes collect and magnify the picture the light waves give.

These radio receivers are called radio telescopes.

There are many kinds of radio telescopes, but all of them consist of two parts--an antenna and a radio receiver. The antenna is often a huge, spectacular-looking metal dish. It may be fitted on a movable stand or mounting so that it can be pointed to any part of the sky. The large metal dish is what people usually think of when they think of a radio telescope. But the radio receiver is an equally important part. Without the receiver, the huge antenna would be of no

use.

Special kinds of radio receivers are needed to magnify or amplify the incoming waves. This is because the waves are often very weak.

After the radio signals are amplified, they may be sent to a loudspeaker that lets the astronomer hear their hissing noise. Usually, however, a record of the radio waves is made on paper. The signals are written down in the form of a wavy line on a strip of paper.

Radio telescopes can operate in all kinds of weather because radio waves are not affected by mist or fog or other kinds of bad weather. They can also be built in any place that is convenient, and don't have to be built on high ground or on mountains as optical telescopes must be.

Radio telescopes help astronomers learn facts about the universe that could not be learned in any other way we now have.