OBSERVING EARTH FROM THE MOON Apollo 16 astronaut John Young used a telescope to photograph star clouds, nebulae, and Earth's outermost atmosphere from the Moon. It was the first telescope used to make astronomical observations from the surface of another planetary body. Dr. George Carruthers, an astronomer at the Naval Research Laboratory, built the original instrument, which is still on the Moon. A backup telescope, restored by Dr. Carruthers is on display in the Museum Photograph courtesy of Naval Research Laboratory Diagram of Apollo telescope EARTH'S "GEOCORONA" Dr. Carruthers' electronic telescope had a 7.5-centimeter (3-inch) aperture lens and was designed to observe in the far-ultraviolet region of the spectrum. This image, taken by the telescope on the Moon, shows Earth's outermost atmosphere, or geocorona, a region where oxygen and nitrogen glow brightly in ultraviolet light. The glowing arcs extending over Earth's nighttime side are produced by oxygen ions (oxygen atoms that have lost an electron) recombining with electrons in the upper atmosphere. Photograph courtesy of Naval Research Laboratory Apollo 16 - the moment of splashdown. The three parachutes, each over 24.3 meters (80 feet) in diameter, lowered the command module with astronauts John W. Young, Thomas K. Mattingly II, and Charles M Duke Jr., to a mid-Pacific landing at 2:45 p.m. EST, April 27, 1972. SNAP-27

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