NASA celebrates Chandra X-Ray Observatory's 15th birthday
Zen Vuong, Pasadena Star-News
PASADENA >> The Chandra space telescope, launched 15 years ago today by NASA's first shuttle mission commanded by a woman, has revolutionized the world's understanding of the universe.Black holes were once science fiction concepts, but the Chandra X-Ray Observatory turned the imagined into reality, said Scott Wolk, a Chandra X-Ray Observatory astrophysicist. "That's really what's out there," Wolk said during an online discussion. "We can't go to a black hole, and we can't go to a pulsar. We can't even go to the nearest exoplanet. But satellites like Chandra can take us there and show us exactly what it looks like. It looks like we're staring out of a port of the Starship Enterprise."
Space Shuttle Columbia blasted off carrying the Chandra on July 23, 1999. Eileen Collins commanded the five-day mission. To commemorate the occasion, NASA hosted an online discussion with an expert panel on Tuesday.The telescope orbits up to 86,500 miles in altitude, far above Earth's X-ray absorbing atmosphere. At the time, the Chandra X-Ray Observatory, which is 45 feet long, was the largest satellite Columbia had ever launched. Chandra, named after the late Indian-American Nobel laureate Subrahmanyan Chandrasekhar, can observe X-rays from particles up to the last second before they fall into a black hole. It is designed to detect x-ray emissions from very hot regions of the universe, such as exploded stars, clusters of galaxies and matter around black holes.
Chandra, which means moon or luminous in Sanskrit, has observed the closest planets and comets as well as the most distant-known quasars, extremely far celestial objects that resemble stars. The telescope has also observed the supermassive black hole at the center of the Milky Way and discovered black holes across the universe.Chandra contributes to research on the nature of dark energy. Its images has made major advances in the study of dark matter by allowing scientists to trace the separation of dark matter from normal matter in collisions between galaxy clusters. "There are no telescopes on the drawing board in the U.S. or world that has the imaging capability that Chandra brings," said Harvey Tananbaum, former director of the Smithsonian Astrophysical Observatory's Chandra X-ray center. "Our colleagues in Europe are working on a project called Athena."The resolution of Chandra's images are about 50 times better than its most advanced predecessor, the High Resolution Imager on the Rontgensatellite. Experts predict Chandra will last at least another decade, Tananbaum said.
Scientists believe all massive galaxies harbor a super-massive black hole, said Julie Hlavacek-Larrondo, assistant professor of physics at Universite de Montreal. An active one pulls in matter and slowly consumes it, causing matter to get heated to about 10 million degrees Fahrenheit, she said. At these temperatures, matter emits a lot of X-rays, which allow scientists to study the gas near black holes.Wolk, though, said Chandra's most tantalizing discovery is something else scientists didn't know existed: planets around other stars, called exoplanets.
"Just like planets that have been discovered when they block optical light from other stars, we've found that exoplanets can also block X-ray light from other stars," he said.Martin Weisskopf, a Chandra Project Scientist, said he looks forward to many more years with the space telescope."Chandra continues to be one of the most successful missions that NASA has ever flown as measured against any metric  -  cost, schedule, technical success and, most of all, scientific discoveries," he said in a statement.
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Chandra Images