telescope

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Keck Observatory

Galileo's telescopes

$refractor at Lick Observatory$

focal length of a lens

$refracting telescope$

Telescope at Birr Castle

Newton's reflecting telescope

Cassegrain reflector

Schmidt telescope

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telescope summary

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Infinite space background with silhouette of telescope. This image elements furnished by NASA.

Telescopes: Seeing Stars

Discover

African Americans demonstrating for voting rights in front of the White House as police and others watch, March 12, 1965. One sign reads, "We demand the right to vote everywhere." Voting Rights Act, civil rights.

Timeline of the American Civil Rights Movement

Close-up of crocodile eye; location unknown (rainforest, reptile).

What’s the Difference Between Alligators and Crocodiles?

World Data Locator Map: Australia

Is Australia an Island?

number zero, 0 balloon

Is Zero an Even or an Odd Number?

Orange basketball on black background and with low key lighting. Homepage 2010, arts and entertainment, history and society

The 10 Greatest Basketball Players of All Time

Queen Elizabeth II addresses at opening of Parliament. (Date unknown on photo, but may be 1958, the first time the opening of Parliament was filmed.)

All 119 References in “We Didn’t Start the Fire,” Explained

Clouds of smoke billow up from controlled burns taking place in the Gulf of Mexico May 19, 2010. The controlled burns were set to reduce the amount of oil in the water following the Deepwater Horizon oil spill. BP spill

The Perils of Industry: 10 Notable Accidents and Catastrophes

telescope: Facts & Related Content

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World’s largest telescopes at risk from Chilean energy project, new analysis confirms • Mar. 17, 2025, 11:06 PM ET (Science | AAAS)

Facts

Also Known As	telescope

Photos and Videos

Keck Observatory

Galileo's telescopes

$refractor at Lick Observatory$

focal length of a lens

$refracting telescope$

Telescope at Birr Castle

Newton's reflecting telescope

Cassegrain reflector

Schmidt telescope

Learn about Lord Rosse's Birr Leviathan telescope and its various important discoveries, the most important being the detailed observations of many nebulae at Birr Castle, Ireland

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Topics

Schmidt telescope Keplerian telescope Galilean telescope multimirror telescope astronomical transit instrument photographic zenith tube Schmidt-Maksutov telescope MMT Observatory Barlow lens transit circle telescope radio telescope X-ray telescope ultraviolet telescope infrared telescope gamma-ray telescope heliostat seeing coelostat siderostat

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Key People

Lewis Morris Rutherfurd.

Lewis Morris Rutherfurd

American astrophysicist

Giuseppe Campani

Italian inventor

Quiz

View of the Andromeda Galaxy (Messier 31, M31).

Astronomy and Space Quiz

Nicolaus Copernicus. Nicolas Copernicus (1473-1543) Polish astronomer. In 1543 he published, forward proof of a Heliocentric (sun centered) universe. Coloured stipple engraving published London 1802. De revolutionibus orbium coelestium libri vi.

All About Astronomy