Britannica AI Icon
Adding us as a Preferred Source tells Google you trust our content, so our articles show up more often in your Google Search, Discover feed, and AI Overviews.
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

Large Binocular Telescope Observatory (LBTO), observatory consisting of two 8.4-metre (28-foot) telescopes located on Mount Graham (3,221 metres [10,567 feet]) in Arizona, U.S. The two telescopes combined have the resolution of a telescope with a mirror 22.8 metres (74.8 feet) across. Construction of the LBTO began in 1997, and the first observations were made in 2005 with one mirror. In 2008 the LBTO made its first observations as a binocular telescope. The LBTO is funded by a collaboration of 19 universities and research institutes in the United States, Italy, and Germany.