List of largest infrared telescopes explained

The largest infrared telescopes for infrared astronomy are listed in terms of diameter of primary mirror. The infrared spectrum with its longer wavelength than visible light has a number of challenges, especially for ground-based observatories but also in space. Notably infrared radiation is emitted by all physical objects above Absolute Zero temperature so telescopes are subject to local interference.

Overall

Infrared observations from Earth's surface are possible in a limited way but can be very dependent on location and atmospheric conditions. Water vapour in the Earth's atmosphere blocks much of the infrared band, although some limited observations are possible and there is a number of infrared observatories.

Sometimes other optical telescopes can make infrared observations if they are equipped with the right detectors, even if they are not dedicated infrared observatories. For ground-based observatories, the location can make a big difference in how much observation is possible.

Name	Image	Effective aperture	Wavelength Coverage	Site	Year(s)	Refs
		6.5m (21.3feet)		University of Tokyo Atacama Obs., Chile	2024	^[1]
James Webb Space Telescope		6.5m (21.3feet)			2022-
		4.1m (13.5feet)	0.85 – 2.3 μm	Paranal Obs., Chile	2008	^[2]
		150abbr=onNaNabbr=on	0.8 - 20 μm	Mauna Kea Obs., Hawaii	1978
		3.5m (11.5feet)	60-672 μm		2009-2013	^[3]
		3.2m (10.5feet)	0.8 - 25 μm		1979	^[4]
		2.5m (08.2feet)	0.3 - 655 μm	747SP Stratosphere	2010-2022	^[5]
		2.3m (07.5feet)	0.4 - 0.8 μm	Jelm mountain, 9656 ft. (2943m)	1977	^[6]

Space telescopes only

Name	Effective aperture cm (in)	Wavelength Coverage	Year	Refs
	650 cm		2021-
	350 cm (138 in)	60-672 μm	2009 - 2013
	240 cm	0.2-1.7 μm	2009 -
Euclid NISP	120 cm	0.92-2.02 μm	2023 -
	85 cm	3-180 μm	2003 - 2020
	68.5 cm	2-200 μm	2006 -2011
	60 cm	2.5-240 μm	1995-1998
	57 cm	5-100 μm	1983	^[7]
	50 cm	4–5.2 & 6–10 μm	2028 (planned)	^[8]
	40 cm	3-25 μm	2009-2011 & 2013 -
	33 cm	4.3-21 μm	1996 - 1997
	15.2 cm	1.7-118 μm	1985 Aug	^[9]
Human Eye	~1 cm	0.39-0.75 μm	-

For comparison

See also

• Lists of telescopes
• Infrared telescope
• List of largest optical reflecting telescopes
• Space Flyer Unit
• Diffuse Infrared Background Experiment (all-sky infrared observation on COBE, launched 1989)

Notes and References

1. http://www.ioa.s.u-tokyo.ac.jp/TAO/intro/intro3.html
2. Emerson, J.P., Sutherland, W.J., McPherson, A.M., Craig, S.C., Dalton, G.B., Ward, A.K. (2005). The Visible & Infrared Survey Telescope for Astronomy. The Messenger
3. News: ESA launches Herschel and Planck space telescopes . BBC . 14 June 2009. 10 November 2011 . Jonathan . Amos.
4. http://irtfweb.ifa.hawaii.edu/information/about.php IRTF homepage
5. Alfred . Krabbe . SOFIA telescope . Proceedings of SPIE: Astronomical Telescopes and Instrumentation . 276–281 . March 2007 . SPIE — The International Society for Optical Engineering . Munich, Germany . astro-ph/0004253. 2000SPIE.4014..276K . 10.1117/12.389103 .
6. http://physics.uwyo.edu/~chip/wiro/ University of Wyoming 2.3-meter Telescope (WIRO)
7. http://herschel.jpl.nasa.gov/relatedMissions.shtml JPL: Herschel Space Observatory: Related Missions
8. http://www.planetary.org/blogs/jason-davis/nasa-to-build-asteroid-telescope.html NASA to Build New Asteroid-Hunting Space Telescope 2019
9. http://adsabs.harvard.edu/full/1992ApJS...78..403K Kent, et al. – Galactic structure from the Spacelab infrared telescope (1992)