A multilayered shield the size of a tennis court will block light from the sun, Earth and moon.įor the awkward shape to fit on a rocket, Webb will launch folded up, then unfurl itself in space (see below, What could go wrong?). But Webb’s massive 6.5-meter-wide mirror and its scientific instruments are exposed to the vacuum of space. Most space telescopes house a single lens or mirror within a tube that blocks sunlight from swamping the dim lights of the cosmos. “But I think it was really worth the wait.” An audacious plan “ It’s been over 25 years,” says cosmologist Wendy Freedman of the University of Chicago. When Webb was an early glimmer in astronomers’ eyes, cosmological revolutions like the discoveries of dark energy and planets orbiting stars outside our solar system hadn’t yet happened. In the years of waiting for Webb to be ready, big scientific questions have emerged. But the science that it can dig into has. Remarkably, the core design of the telescope hasn’t changed much. The mission was originally scheduled to launch between 20, but a series of budget and technical issues pushed its start date back more than a decade. Scientists have been drafting and redrafting their dreams and plans for this unique tool since 1989. When it launches later this year, the observatory will be the largest and most complex telescope ever sent into orbit. Webb is an international program led by NASA with its partners, ESA (European Space Agency), and CSA (Canadian Space Agency).The James Webb Space Telescope has been a long time coming. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. The James Webb Space Telescope is the world's premier space science observatory. Webb’s detailed image of WR 124 preserves forever a brief, turbulent time of transformation, and promises future discoveries that will reveal the long-shrouded mysteries of cosmic dust. Similar dying stars first seeded the young universe with heavy elements forged in their cores – elements that are now common in the current era, including on Earth. Stars like WR 124 also serve as an analog to help astronomers understand a crucial period in the early history of the universe. Now those questions can be investigated with real data. Before Webb, dust-loving astronomers simply did not have enough detailed information to explore questions of dust production in environments like WR 124, and whether the dust grains were large and bountiful enough to survive the supernova and become a significant contribution to the overall dust budget. The telescope’s Mid-Infrared Instrument (MIRI) reveals the clumpy structure of the gas and dust nebula of the ejected material now surrounding the star. Webb’s Near-Infrared Camera (NIRCam) balances the brightness of WR 124’s stellar core and the knotty details in the fainter surrounding gas. Webb opens up new possibilities for studying details in cosmic dust, which is best observed in infrared wavelengths of light. The universe is operating with a dust budget surplus. Despite the many essential roles that dust plays, there is still more dust in the universe than astronomers’ current dust-formation theories can explain. Dust is integral to the workings of the universe: It shelters forming stars, gathers together to help form planets, and serves as a platform for molecules to form and clump together-including the building blocks of life on Earth. The origin of cosmic dust that can survive a supernova blast and contribute to the universe’s overall “dust budget” is of great interest to astronomers for multiple reasons. As the ejected gas moves away from the star and cools, cosmic dust forms and glows in the infrared light detectable by Webb. The star WR 124 is 30 times the mass of the Sun and has shed 10 Suns’ worth of material-so far. Wolf-Rayet stars are in the process of casting off their outer layers, resulting in their characteristic halos of gas and dust. Massive stars race through their lifecycles, and only some of them go through a brief Wolf-Rayet phase before going supernova, making Webb’s detailed observations of this rare phase valuable to astronomers. The star is 15,000 light-years away in the constellation Sagitta. Webb shows the star, WR 124, in unprecedented detail with its powerful infrared instruments. The rare sight of a Wolf-Rayet star – among the most luminous, most massive, and most briefly-detectable stars known – was one of the first observations made by NASA’s James Webb Space Telescope in June 2022.
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