Editing Observational astronomy (section)

=== Radio astronomy ===
With the discovery of [[radio]] waves, [[radio astronomy]] began to emerge as a new discipline in astronomy. The long wavelengths of radio waves required much larger collecting dishes in order to make images with good resolution, and later led to the development of the multi-dish [[interferometer]] for making high-resolution [[aperture synthesis]] radio images (or "radio maps"). The development of the microwave horn receiver led to the discovery of the [[cosmic microwave background radiation|microwave background radiation]] associated with the [[Big Bang]].<ref>{{Cite journal|last1=Dicke|first1=R. H.|last2=Peebles|first2=P. J. E.|last3=Roll|first3=P. G.|last4=Wilkinson|first4=D. T.|date=July 1965|title=Cosmic Black-Body Radiation.|journal=The Astrophysical Journal|volume=142|pages=414–419|doi=10.1086/148306|issn=0004-637X|bibcode=1965ApJ...142..414D}}</ref>

Radio astronomy has continued to expand its capabilities, even using [[HALCA|radio astronomy satellites]] to produce interferometers with baselines much larger than the size of the Earth. However, the ever-expanding use of the radio spectrum for other uses is gradually drowning out the faint radio signals from the stars. For this reason, in the future radio astronomy might be performed from shielded locations, such as the [[Far side (Moon)|far side]] of the [[Moon]].