Editing Observatory (section)

===Space-based observatories===
{{main|Space telescope}}
[[File:Hubble Space Telescope (27946391011).jpg|thumb|left|The [[Hubble Space Telescope]] in Earth's orbit]]
Space-based observatories are telescopes or other instruments that are located in [[outer space]], many in [[orbit]] around the Earth. Space telescopes can be used to observe astronomical objects at wavelengths of the electromagnetic spectrum that cannot penetrate the [[Earth's atmosphere]] and are thus impossible to observe using ground-based telescopes. The Earth's atmosphere is [[Opacity (optics)|opaque]] to [[ultraviolet]] radiation, [[X-rays]], and [[gamma rays]] and is partially opaque to [[infrared]] radiation so observations in these portions of the electromagnetic spectrum are best carried out from a location above the atmosphere of our planet.<ref>{{cite book| last = Chaisson| first = Eric|author2=McMillan, Steve| title = Astronomy Today, Fourth Edition| publisher = [[Prentice Hall]]| date = 2002}}</ref> Another advantage of space-based telescopes is that, because of their location above the Earth's atmosphere, their images are free from the effects of atmospheric turbulence that plague ground-based observations.<ref>{{cite web|publisher=NASA|url=https://history.nasa.gov/hubble/index.html|title=A Brief History of the Hubble Space Telescope: Why a Space Telescope?|access-date=2006-08-14}}</ref> As a result, the [[angular resolution]] of space telescopes such as the [[Hubble Space Telescope]] is often much smaller than a ground-based telescope with a similar [[aperture]]. However, all these advantages do come with a price. Space telescopes are much more expensive to build than ground-based telescopes. Due to their location, space telescopes are also extremely difficult to maintain. The Hubble Space Telescope was able to be serviced by the [[Space Shuttle]]s while many other space telescopes cannot be serviced.