Editing Observational astronomy (section)

== Developments and diversity ==
[[File:Under the Spell of the Magellanic Clouds.jpg|thumb|250px|[[Atacama Large Millimeter Array|ALMA]] is the world's most powerful telescope for studying the Universe at submillimeter and millimeter wavelengths.<ref>{{cite news|title=Under the Spell of the Magellanic Clouds|url=http://www.eso.org/public/images/potw1315a/|access-date=17 April 2013|newspaper=ESO Picture of the Week}}</ref> ]]

In addition to examination of the universe in the optical spectrum, astronomers have increasingly been able to acquire information in other portions of the electromagnetic spectrum. The earliest such non-optical measurements were made of the thermal properties of the [[Sun]]. Instruments employed during a solar eclipse could be used to measure the radiation from the [[solar corona|corona]].

[[Image:Green Bank Telescope.jpg|thumb|right|250px|[[Green Bank Telescope|Fully-steerable radio telescope]] in [[Green Bank, West Virginia]]]]

=== 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]].

=== Late 20th-century developments ===
The last part of the twentieth century saw rapid technological advances in astronomical instrumentation. Optical telescopes were growing ever larger, and employing [[adaptive optics]] to partly negate atmospheric blurring. New telescopes were launched into space, and began observing the universe in the [[infrared]], [[ultraviolet]], [[x-ray]], and [[gamma ray]] parts of the electromagnetic spectrum, as well as observing [[cosmic ray]]s. Interferometer arrays produced the first extremely high-resolution images using [[aperture synthesis]] at radio, infrared and optical wavelengths. Orbiting instruments such as the [[Hubble Space Telescope]] produced rapid advances in astronomical knowledge, acting as the workhorse for visible-light observations of faint objects. New space instruments under development are expected to directly observe planets around other stars, perhaps even some Earth-like worlds.

In addition to telescopes, astronomers have begun using other instruments to make observations.

=== Other instruments ===
[[Neutrino astronomy]] is the branch of astronomy that observes astronomical objects with [[neutrino detector]]s in special observatories, usually huge underground tanks. [[Nuclear reaction]]s in stars and [[supernova]] explosions produce very large numbers of [[neutrino]]s, very few of which may be detected by a [[neutrino telescope]]. Neutrino astronomy is motivated by the possibility of observing processes that are inaccessible to [[telescope|optical telescope]]s, such as the [[Solar core|Sun's core]].

[[Gravitational wave]] detectors are being designed that may capture events such as collisions of massive objects such as [[neutron star]]s or [[black hole]]s.<ref>{{cite web|title=Planning for a bright tomorrow: Prospects for gravitational-wave astronomy with Advanced LIGO and Advanced Virgo|url=http://www.ligo.org/science/Publication-ObservingScenario/index.php|publisher=[[LIGO Scientific Collaboration]]|access-date=31 December 2015}}</ref>

[[Robot]]ic [[spacecraft]] are also being increasingly used to make highly detailed observations of [[planet]]s within the [[Solar System]], so that the field of [[planetary science]] now has significant cross-over with the disciplines of [[geology]] and [[meteorology]].