Editing Astronomy (section)

=== Optical astronomy ===
[[File:The Keck Subaru and Infrared obervatories.JPG|thumb|The [[Subaru Telescope]] (left) and [[Keck Observatory]] (center) on [[Mauna Kea]], both examples of an observatory that operates at near-infrared and visible wavelengths. The [[NASA Infrared Telescope Facility]] (right) is an example of a telescope that operates only at near-infrared wavelengths.]]
{{Main|Optical astronomy}}
Historically, optical astronomy, which has been also called visible light astronomy, is the oldest form of astronomy.<ref name="moore1997">{{cite book
|author=Moore, P.
|title=Philip's Atlas of the Universe
|date=1997
|publisher=George Philis Limited
|location=Great Britain
|isbn=978-0-540-07465-5}}</ref> Images of observations were originally drawn by hand. In the late 19th century and most of the 20th century, images were made using photographic equipment. Modern images are made using digital detectors, particularly using [[charge-coupled device]]s (CCDs) and recorded on modern medium. Although visible light itself extends from approximately 4000 [[Ångstrom|Å]] to 7000 Å (400 [[nanometre|nm]] to 700&nbsp;nm),<ref name="moore1997"/> that same equipment can be used to observe some [[near-ultraviolet]] and [[near-infrared]] radiation.{{cn|date=March 2025}}