"When it comes to these distant galaxies, the Wide Field Camera 3 runs out of wavelength," said Kimble. Webb, Kimble said, is now positioned to surpass that legacy. It was the Wide Field Camera 3 that opened some of the best views into the early universe. (Image credit: NASA/JPL-Caltech) Untangling early star and galaxy formation NASA's previous infrared telescope, Spitzer, was much smaller and therefore much less sensitive. Where the Hubble Space Telescope, or the recently retired infrared telescope Spitzer, could provide only a rough estimate of an ancient galaxy's age and chemical composition, Webb will deliver with precision, added Kimble, who previously worked on instruments for the Hubble Space Telescope, including the Wide Field Camera 3, Hubble's most advanced instrument, which was installed during the final servicing mission in 2009. These improvements in the resolution of infrared imaging are critical for imaging the furthest reaches of the universe. "In some of those mid-infrared wavelengths, there's probably an advantage of 1,000 for some kinds of observations." "The James Webb Space Telescope instruments are a factor 10 to 100 better than anything previously available," Randy Kimble, JWST project scientist for integration, test and commissioning at NASA's Goddard Space Flight Center in Greenbelt, Maryland, told. As different chemical elements absorb light at different wavelengths, astronomers will be able to reconstruct what stars, nebulas, galaxies and planets within James Webb's Space Telescope's sight are made of. This is done with a technique known as spectroscopy, which looks at how matter in the universe absorbs light. The James Webb Space Telescope's giant mirror will feed the light of stars and galaxies into four cutting edge instruments designed not only to take images, but also to analyze the chemical composition of the near and distant universe. So what exactly will all those pixels (in combination with all the other aspects of the mission that make it so ground-breaking) enable James Webb Space Telescope to do? "We have many more infrared pixels than Hubble had optical pixels when it was launched." And we have lots of them," McCaughrean said. "The detectors on JWST have 2000 by 2000 pixels. The technology has come a long way since Hubble's early years, and the James Webb Space Telescope project has been pushing it further along the way. NASA's James Webb Space Telescope (JWST), will orbit the sun 1 million miles (1.5 million kilometers) from Earth. NICMOS, consisting of three infrared detectors, each of which had 256 by 256 pixels, opened the first door for Hubble into the infrared universe. to work on the Near Infrared Camera and Multi-Object Spectrometer (NICMOS), the first infrared detector fitted on the Hubble Space Telescope during its second servicing mission in 1997. We had 58 times 62 pixels, and that was 4,000 times more than everybody else had, because they only had one." My PhD thesis was all about the first camera which could take 2D infrared images. "In the 1980s, infrared pictures were taken with one detector scanning the sky one pixel at a time," said McCaughrean. McCaughrean, then a PhD student at the University of Edinburgh in Scotland, was one of those scientists developing early infrared detectors, a technology that has now reached its culmination in four cutting-edge scientific instruments of the James Webb Space Telescope. These early galaxies do emit visible light, but because of their distance, the wavelength of this light gets stretched into the infrared part of the electromagnetic spectrum by the so-called redshift. Hubble was built to detect visible and ultraviolet light. This missing piece of technology was infrared detectors that would be able to collect the faint light coming from those early stars and galaxies more than 13 billion light-years away. The technology that would eventually enable this observatory, now known as the James Webb Space Telescope (originally called the Next Generation Space Telescope), to see that mythical first light in the universe, had yet to be developed.
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