About the James Webb Space Telescope
Release Date: May 14, 2018 9:30AM (EDT)
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From its orbit around the Sun at Lagrange Point 2 (L2), nearly 1.5 million kilometers (940,000 miles) from Earth, Webb has a relatively unobstructed view of the universe. This orbit allows the telescope to stay in line with the Earth as it moves around the Sun, assisting Webb’s large sunshield in protecting its infrared instruments from the light and heat of the Sun, Earth, and Moon.
Webb’s large, segmented primary mirror gives it unprecedented light-gathering ability. Each of its 18 hexagonal-shaped mirror segments is 1.3 meters (4.3 feet) in diameter. Together they create a 6.5 meters (21.6 feet) surface. In contrast, the Hubble Space Telescope’s primary mirror is a single, round, 2.4-meter mirror.
Webb detects light wavelengths on the electromagnetic spectrum from visible red to mid-infrared. Its four instruments will provide wavelength coverage from 0.6 to 28 micrometers (or microns; 1 micron is 1.0 by 10-6 meters). The infrared part of the spectrum spans from about 0.75 microns to a few hundred microns.