List of largest infrared telescopes

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.

Atmospheric windows in the infrared: much of this type of light is blocked when viewed from the Earth's surface.

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
TAO telescope		6.5 m (260 in)	0.9-38 μm	University of Tokyo Atacama Obs., Chile	2024	[1]
James Webb Space Telescope		6.5 m (260 in)	0.6-28.5 μm	Space, Sun-Earth L2	2022-
VISTA		4.1 m (160 in)	0.85 – 2.3 μm	Paranal Obs., Chile	2008	[2]
United Kingdom Infrared Telescope		3.8 m (150 in)	0.8 - 20 μm	Mauna Kea Obs., Hawaii	1978
Herschel Space Observatory		3.5 m (140 in)	60-672 μm	Space, Sun-Earth L2	2009-2013	[3]
Infrared Telescope Facility		3.2 m (130 in)	0.8 - 25 μm	Mauna Kea, Hawaii	1979	[4]
SOFIA		2.5 m (98 in)	0.3 - 655 μm	747SP; Stratosphere	2010-2022	[5][6]
Wyoming Infrared Observatory		2.3 m (91 in)	0.4 - 0.8 μm	Jelm mountain, 9656 ft. (2943m)	1977	[7]

Space telescopes only

The mirror of the James Webb Space Telescope is coated with gold because of its ability to reflect infrared light. Optical telescopes typically have used aluminum or silver.

Infrared observations can see objects hidden in visible light, such as HUDF-JD2 shown.

Name	Effective aperture cm (in)	Wavelength Coverage	Year	Refs
James Webb (JWST)	650 cm	0.6-28.5 μm	2021-
Herschel Obs.	350 cm (138 in)	60-672 μm	2009 - 2013	[3]
Hubble WFC3	240 cm	0.2-1.7 μm	2009 -
Euclid NISP	120 cm	0.92-2.02 μm	2023 -
Spitzer	85 cm	3-180 μm	2003 - 2020	[5]
Akari	68.5 cm	2-200 μm	2006 -2011	[5]
ISO	60 cm	2.5-240 μm	1995-1998	[5]
IRAS	57 cm	5-100 μm	1983	[5]
NEO Surveyor	50 cm	4–5.2 & 6–10 μm	2028 (planned)	[8]
WISE/NEOWISE	40 cm	3-25 μm	2009-2011 & 2013 -	[5]
MSX	33 cm	4.3-21 μm	1996 - 1997
Spacelab IRT	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)

References

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. Amos, Jonathan (14 June 2009). "ESA launches Herschel and Planck space telescopes". BBC. Retrieved 10 November 2011.
4. IRTF homepage
5. JPL: Herschel Space Observatory: Related Missions
6. Krabbe, Alfred (March 2007). "SOFIA telescope". Proceedings of SPIE: Astronomical Telescopes and Instrumentation. Munich, Germany: SPIE — The International Society for Optical Engineering. pp. 276–281. arXiv:astro-ph/0004253. Bibcode:2000SPIE.4014..276K. doi:10.1117/12.389103.
7. University of Wyoming 2.3-meter Telescope (WIRO)
8. NASA to Build New Asteroid-Hunting Space Telescope 2019
9. Kent, et al. – Galactic structure from the Spacelab infrared telescope (1992).