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[p style="text-align: center;"]NASA's James Webb Space Telescope, scheduled for launch in 2021, will probe the cosmos to uncover the history of the universe from the Big Bang to alien planet formation and beyond. [p]
[br][p]It will focus on four main areas: first light in the universe, assembly of galaxies in the early universe, birth of stars and protoplanetary systems, and planets (including the origins of life.)[p] The James Webb Space Telescope (JWST) will launch on an [span style="font-weight: bold;"]Ariane 5[/span] rocket from French Guiana, then take 30 days to fly a million miles to its permanent home: a Lagrange point, or a gravitationally stable location in space.[p]
[br][p] It will orbit around L2, a spot in space near Earth that lies opposite from the sun. This has been a popular spot for several other space telescopes, including the Herschel Space Telescope and the Planck Space Observatory.
The powerful $8.8 billion spacecraft is also expected to take amazing photos of celestial objects like its predecessor, the Hubble Space Telescope.[p] Luckily for astronomers, the Hubble Space Telescope remains in good health and it's probable that the two telescopes will work together for JWST's first years. JWST will also look at exoplanets that the Kepler Space Telescope found, or follow up on real-time observations from ground space telescopes.[h2 id="instruments-on-board"]Instruments on board[/h2][p]The JWST will come equipped with four science instruments.[h3][span style="text-decoration-line: underline; font-style: italic;"]1--Near-Infrared Camera (NIRCam)[/span][/h3][p style="text-align: center;"]
[br][p] Provided by the University of Arizona, this infrared camera will detect light from stars in nearby galaxies and stars within the Milky Way. It will also search for light from stars and galaxies that formed early in the universe's life. NIRCam will be outfitted with coronagraphs that can block a bright object's light, making dimmer objects near those stars (like planets) visible. [h3]2--[span style="font-style: italic; text-decoration-line: underline;"]Near-Infrared Spectrograph (NIRSpec)[/span][/h3][p style="text-align: center;"]
[br][p] NIRSpec will observe 100 objects simultaneously, searching for the first galaxies that formed after the Big Bang. NIRSpec was provided by the European Space Agency with help from NASA's Goddard Space Flight Center.[h3]3-- [span style="font-style: italic; text-decoration-line: underline;"]Mid-Infrared Instrument (MIRI)[/span][/h3][div style="text-align: center;"]
[span style="font-style: italic; text-decoration-line: underline;"][br][/span][/div][p] MIRI will produce amazing space photos of distant celestial objects, following in Hubble's tradition of astrophotography. The spectrograph that is a part of the instrument will allow scientists to gather more physical details about distant objects in the universe. MIRI will detect distant galaxies, faint comets, forming stars and objects in the Kuiper Belt. MIRI was built by the European Consortium with the European Space Agency and NASA's Jet Propulsion Laboratory. [h3]4--[span style="text-decoration-line: underline; font-style: italic;"]Fine Guidance Sensor/Near InfraRed Imager and Slitless Spectrograph (FGS/NIRISS)[/span][/h3][div]
[span style="text-decoration-line: underline; font-style: italic;"][br][/span][/div][p] This Canadian Space Agency-built instrument is more like two instruments in one. The FGS component is responsible for keeping the JWST pointed in exactly the right direction during its science investigations. NIRISS will scope out the cosmos to find signatures of the first light in the universe and seek out and characterize alien planets.[p style="text-align: center;"]
[br][p]The telescope will also sport a tennis court-size sunshield and a 21.3-foot (6.5 meters) mirror — the largest mirror ever launched into space. Those components will not fit into the rocket launching the JWST, so both will unfurl once the telescope is in space.[br] |
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发表于 2019-04-05 22:07:47
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