via: https://www.revolver.news/2021/12/after-14-year-delay-james-webb-telescope-set-for-xmas-launch/
Webb Telescope Launch Could Shift Our Understanding of the Early Universe
After years of delay, the $10 billion observatory, successor to the Hubble, is set to launch into space on Dec. 25
https://www.wsj.com/articles/webb-telescope-launch-could-shift-our-understanding-of-the-early-universe-11640341802
https://archive.fo/zQP9P
A new era of astronomy will dawn Saturday, Dec. 25, when the James Webb Space Telescope, the largest and most powerful space telescope ever constructed, lifts off from the edge of a South American jungle and begins a decadelong mission to catch the glitter of the first stars at the birth of the universe.
With six times the light-gathering power of the Hubble Space Telescope, which preceded it into space more than a generation ago, the Webb telescope will peer deeper into the cosmos—and farther back in time—to open a window on the universe as it took shape soon after the Big Bang.
“We want to look at those first galaxies growing,” said John Mather, a Nobel Prize-winning astrophysicist and the senior project scientist for the Webb telescope at the National Aeronautics and Space Administration’s Goddard Space Flight Center in Greenbelt, Md. “One of our top goals is to see how stars grow with their young planets.”
Astronomers will also use the new telescope to probe black holes at the centers of galaxies, search for the chemical signatures of life on extrasolar planets and, closer to home, study the frozen oceans on moons at the edge of our own solar system.
The $10 billion, truck-size telescope, now nestled inside the nose cone of a rocket, is poised for launch from Europe’s Spaceport along the Atlantic coast in French Guiana. Once it clears Earth’s atmosphere, it will set course on a 29-day voyage to a spot four times as far away as the moon. Plans call for the spacecraft to orbit the sun at this spot, called the second Lagrange point, at least through 2026, collecting distant starlight with its huge, gold-coated mirror and beaming back a steady stream of images and data.
The Webb’s ultrasensitive infrared sensors are designed to capture light emitted more than 13.6 billion years ago by primordial stars, gargantuan furnaces that were hundreds of times larger than any stars shining today. It could reveal the earliest star clusters and supernovas, where almost all the elements were forged.
“We want to see the first objects that formed as the universe cooled down after the Big Bang,” Dr. Mather said. “We don’t know exactly when the universe made the first stars and galaxies, or how for that matter. One way or another, the first stars must have influenced our own history, beginning with stirring up everything and producing the other chemical elements besides hydrogen and helium.”
Stretched by time and distance, that first starlight has shifted from visible or ultraviolet light into redder wavelengths that are invisible to the Hubble Space Telescope and most terrestrial telescopes, because moisture in the atmosphere strongly absorbs infrared radiation.
By looking in the infrared, the Webb telescope also will be able to see through the cosmic dust that ordinarily obscures exoplanets, which are those outside our solar system orbiting other stars, and galaxies.
“The Webb will be able to see in the infrared stars and galaxies that were a hundred times fainter than was previously possible,” said Klaus Pontoppidan, a project scientist at the Space Telescope Science Institute in Baltimore, which will manage the telescope once it is in space.
The Webb also carries an advanced chemical analyzer called the Near Infrared Spectrograph that collects data about variations in light to reveal the temperatures, masses and chemical compositions of stars and planets.
“We will be able to take a hundred spectra or more at the same time in a single exposure,” said Antonella Nota, a Webb project scientist with the European Space Agency. “Images are worth a thousand words; spectra, for astronomers, are worth a thousand images.”
In the telescope’s first year of operation, astronomers plan to use it to analyze atmospheres of 65 planets that orbit stars light-years away from our own solar system, seeking evidence of water, carbon dioxide, methane and ammonia. “We will be able to look in the atmospheres of the planets to identify elements that are signs of life as we know it,” said Begoña Vila, an instrument systems engineer for the telescope.
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