Keck Observatory

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Keck Observatory

Keck Observatory

The hexagonal-segmented 10-metre primary mirror of the Keck I telescope. A technician riding a bucket crane (right of centre) is seen cleaning the mirror.

Keck Observatory

Mauna Kea Observatory

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Britannica’s U.S. Presidents Bingo

Apollo 11 Lunar Module with its four landing-gear footpads deployed. This photograph was taken from the Command Module as the two spacecraft moved apart above the Moon.

5 Unforgettable Moments in the History of Spaceflight and Space Exploration

Voskhod. The first human in space. Three stills from an external movie camera on the Soviet Voskhod 2 records pilot Aleksey Leonov historic 10 min. spacewalk, March 18, 1965. Leonov extravehicular activities (EVA) was the first human to ever walk in space

The First Space Walk

After a perfect launch, spectators try to catch a last glimpse of Space Shuttle Columbia, barely visible at the top end of the twisted column of smoke.

7 Accidents and Disasters in Spaceflight History

Close up of a hand placing a ballot in a ballot box. Election vote voter voting

Have Any U.S. Presidents Decided Not to Run For a Second Term?

Discover

Lake Mead (the impounded Colorado River) at the Hoover Dam. The light-coloured band of rock above the shoreline shows the decrease in water level in the first few years of the 21st century.

6 Lakes That Are Drying Up

The Colosseum, Rome, Italy. Giant amphitheatre built in Rome under the Flavian emperors. (ancient architecture; architectural ruins)

New Seven Wonders of the World

Figure 13: A Maxim machine gun, belt-fed and water-cooled, operated by German infantrymen, World War I.

7 Deadliest Weapons in History

Close up of books. Stack of books, pile of books, literature, reading. Homepage 2010, arts and entertainment, history and society

12 Novels Considered the “Greatest Book Ever Written”

Bristlecone pine (Pinus Longaeva) on the slope of Mount Washington in Great Basin National Park in the Nevada desert.

How Can Some Trees Survive for Thousands of Years?

Cathedrale St.Jean in Lyon, France has a 14th-century astronomical clock that shows religious feast days till the year 2019; Perpetual Calendar

Ten Days That Vanished: The Switch to the Gregorian Calendar

Periodical Cicada, Adult, Magicicada spp. Requires 17 years to complete development. Nymph splits its skin, and transforms into an adult. Feeds on sap of tree roots. Northern Illinois Brood. This brood is the largest emergence of cicadas anywhere

Why Do Some Cicadas Appear Only Every 17 Years?

Keck Observatory: Related Content

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News •

NASA’s Webb Spots Clouds On Titan, Saturn’s ‘Earth-Like’ Moon • May 17, 2025, 9:40 AM ET (Forbes)

Photos

Keck Observatory

Keck Observatory

The hexagonal-segmented 10-metre primary mirror of the Keck I telescope. A technician riding a bucket crane (right of centre) is seen cleaning the mirror.

Keck Observatory

Mauna Kea Observatory

See All Images →

Topics

Laser Interferometer Gravitational-Wave Observatory Arecibo Observatory Very Large Telescope Royal Greenwich Observatory Palomar Observatory Mauna Kea Observatory FAST Jodrell Bank Observatory Mount Wilson Observatory Gran Telescopio Canarias

Quiz

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

Astronomy and Space Quiz