text: Several reasons:\n\n1) Radio waves go through the earth's atmosphere, so we can detect them and stay on the ground. This is also true for visible light, but is not true for UV, gamma, and other regions of the spectrum.\n\n2) Hydrogen has a particularly noticeable radio frequency and that helps us to make maps of where things are in the universe.\n\n3) It is relatively easy to do interferometry with radio waves, so more resultion can be obtained in some studies.\n\n4) Radio waves go through dust fairly easily, unlike visible light. THis allows us to 'see' things with radio that we could not see otherwise.