HOW CAN SATELLITES PROVIDE PHOTOGRAPHS OF THE UNIVERSE,GALAXIES AND PLANETS IF THEY DO NOT COME DOWN?

One of my friend told me that,you must be seeing programmes on television.In the TV station, a scene in motion and its accompanying sounds are converted inot electric signals.These signals are transmitted.The TV receiver set reconverts these signals inot visible and audio images.

In the case of photographs taken by satellites,a similar principle is used.The electronic system in the camera transforms the light signals into radio waves and amplifies them,before transmitting them through a device called tranponder.The receiving station on earth converts them back into visual images