What do astronomers use to detect radio waves and how do they use that instrument in space?
A radio receiver. It’s fed by a radio telescope, usually a parabolic dish which focuses the incoming signals onto a horn antenna. Immediately after this antenna is a very low noise amplifier which tends to impose it’s good performance on to that of the whole system. The output of this amplifier may well be filtered and amplified further before it is connected to the receiver. This receiver will have more facilities than your standard home radio. But it still does a similar job, changing the radio signals into a form where it can be measured and recorded. The radio telescope can be pointed in any particular direction and the receiver tuned to any particular frequency for the search in hand. Different frequencies are emitted by various phenomena in space, so this tells scientists what may be happening in any specific part of space.
