James Webb Space Telescope

The James Webb Space Telescope (JWST) is a <a href="/facts/Space_telescope/BtI46sDX">space telescope</a> designed to conduct <a href="/facts/Infrared_astronomy/WEmAadyf">infrared astronomy</a>. As the largest telescope in space, it is equipped with high-resolution and high-sensitivity instruments, allowing it to view objects too old, <a href="/facts/List_of_the_most_distant_astronomical_objects/xutYjJn3">distant</a>, or faint for the <a href="/facts/Hubble_Space_Telescope/NQeIf0vw">Hubble Space Telescope</a>. This enables investigations across many fields of <a href="/facts/Astronomy/0ArJVM1p">astronomy</a> and <a href="/facts/Cosmology/yM19zM7Y">cosmology</a>, such as observation of the <a href="/facts/Population_III_star/8ur1qDRK">first stars</a> and the <a href="/facts/Galaxy_formation_and_evolution/uAPtXxr4">formation of the first galaxies</a>, and detailed atmospheric characterization of <a href="/facts/Potentially_habitable_exoplanet/zNYbuyTV">potentially habitable exoplanets</a>.
Although the Webb's mirror diameter is 2.7 times larger than that of the Hubble Space Telescope, it produces images of comparable <a href="/facts/Optical_resolution/TcLkPYFw">resolution</a> because it observes in the longer-wavelength infrared spectrum. The longer the wavelength of the spectrum, the larger the information-gathering surface required (mirrors in the infrared spectrum or antenna area in the millimeter and radio ranges) for an image comparable in clarity to the visible spectrum of the Hubble Space Telescope.
The Webb was launched on 25 December 2021 on an Ariane 5 rocket from <a href="/facts/Kourou/wvDVpjpJ">Kourou</a>, French Guiana. In January 2022 it arrived at its destination, a solar orbit near the Sun–Earth <a href="/facts/Lagrange_point/XCAN4o3P">L2 Lagrange point</a>, about 1.5 million kilometers (930,000 mi) from Earth. <a href="/facts/Webb%2527s_First_Deep_Field/cqJADG2o">The telescope's first image</a> was released to the public on 11 July 2022.
The U.S. <a href="/facts/National_Aeronautics_and_Space_Administration/TIMCV0yV">National Aeronautics and Space Administration</a> (NASA) led Webb's design and development and partnered with two main agencies: the <a href="/facts/European_Space_Agency/L8YRNV0C">European Space Agency</a> (ESA) and the <a href="/facts/Canadian_Space_Agency/zL2njRvS">Canadian Space Agency</a> (CSA). The NASA <a href="/facts/Goddard_Space_Flight_Center/WfoEKknM">Goddard Space Flight Center</a> in <a href="/facts/Maryland/tVy9fC1n">Maryland</a> managed telescope development, while the <a href="/facts/Space_Telescope_Science_Institute/kPnzlp8h">Space Telescope Science Institute</a> in <a href="/facts/Baltimore/ncJvTzBU">Baltimore</a> on the <a href="/facts/Homewood_Campus_of_Johns_Hopkins_University/yXdurLpY">Homewood Campus of Johns Hopkins University</a> operates Webb. The primary contractor for the project was <a href="/facts/Northrop_Grumman/M6keKE1A">Northrop Grumman</a>.
The telescope is named after <a href="/facts/James_E._Webb/c66DzulP">James E. Webb</a>, who was the <a href="/facts/List_of_administrators_and_deputy_administrators_of_NASA/IltN5emr">administrator of NASA</a> from 1961 to 1968 during the <a href="/facts/Project_Mercury/H8zqFzbC">Mercury</a>, <a href="/facts/Project_Gemini/7PYE3AV4">Gemini</a>, and <a href="/facts/Apollo_program/IC1Ek1Ao">Apollo</a> programs.
Webb's <a href="/facts/Primary_mirror/juxwTBYa">primary mirror</a> consists of 18 hexagonal <a href="/facts/Segmented_mirror/UTGzsy5u">mirror segments</a> made of <a href="/facts/Gold/1znknojp">gold</a>-plated <a href="/facts/Beryllium/dv295voP">beryllium</a>, which together create a 6.5-meter-diameter (21 ft) mirror, compared with Hubble's 2.4 m (7 ft 10 in). This gives Webb a <a href="/facts/Aperture/8PV11GQm">light-collecting area</a> of about 25 m2 (270 sq ft), about six times that of Hubble. Unlike Hubble, which observes in the <a href="/facts/Ultraviolet/kncBUqn5">near ultraviolet</a> and <a href="/facts/Visible_spectrum/frPBh8o5">visible</a> (0.1 to 0.8 <a href="/facts/%25CE%259Cm/7eDFxD2L">μm</a>), and <a href="/facts/Near_infrared/44XdJNcc">near infrared</a> (0.8–2.5 μm) spectra, Webb observes a lower frequency range, from long-wavelength visible <a href="/facts/Light/jeofpMn4">light</a> (red) through mid-infrared (0.6–28.5 μm). The telescope must be kept extremely cold, below 50 K (−223 °C; −370 °F), so that the <a href="/facts/Infrared/44XdJNcc">infrared</a> light <a href="/facts/Black-body_radiation/f0fHghDy">emitted</a> by the telescope itself does not interfere with the collected light. Its five-layer <a href="/facts/Sunshield_(JWST)/3YNe901e">sunshield</a> protects it from warming by the Sun, Earth, and Moon.
Initial designs for the telescope, then named the Next Generation Space Telescope, began in 1996. Two concept studies were commissioned in 1999, for a potential launch in 2007 and a US$1 billion budget. The program was plagued with enormous cost overruns and delays. A major redesign was accomplished in 2005, with construction completed in 2016, followed by years of exhaustive testing, at a total cost of US$10 billion.

James Webb Space Telescope open-in-new

James Webb Space Telescope