A NASA spacecraft scanning for the most powerful explosions in the universe has captured a photo of Comet ISON, an icy wanderer that could potentially dazzle stargazers when it swings close to the sun later this year.
NASA's Swift satellite, which is typically used to track intense gamma-ray bursts from distant stars, photographed Comet ISON on Jan. 30, with the space agency unveiling the photo today (March 29). By tracking the comet over the last two months, Swift has allowed astronomers to learn new details about how large the comet is and how fast it is spewing out gas and dust.
"Comet ISON has the potential to be among the brightest comets of the last 50 years, which gives us a rare opportunity to observe its changes in great detail and over an extended period," said Lead Investigator Dennis Bodewits, an astronomer with University of Maryland at College Park (UMCP) who helped obtain the new image.
Some astronomers have predicted that ISON could be the "Comet of the Century" when it makes its closest approach to the sun in late November. But a recent analysis found that the comet is not brightening as expected, and may have a ways to go to meet such expectations.
Comet ISON was first discovered in September 2012 by Russian astronomers Vitali Nevski and Artyom Novichonok using the International Scientific Optical Network (ISON) located near Kislovodsk. The comet's official designation is Comet C/2012 S1 (ISON).
Bodewits and his university colleagues teamed up with the Lowell Observatory in Flagstaff, Ariz., to capture new views of Comet ISON using the Swift spacecraft. The satellite's Jan. 30 photo shows the comet as a bright, fuzzy white ball. At the time, Comet ISON was about 375 million miles (670 million kilometers) from Earth and 460 million miles (740 million km) from the sun.
"Using images acquired over the last two months from Swift's Ultraviolet/Optical Telescope (UVOT), the team has made initial estimates of the comet's water and dust production and used them to infer the size of its icy nucleus," NASA officials wrote in a statement.
Swift's observations revealed that Comet ISON is currently shedding about 112,000 pounds (51,000 kilograms) of dust and about 130 pounds (60 kg) of water every minute, an odd mismatch for such an anticipated comet.
more here: http://www.space.com/20440-comet-ison-photo-nasa-satellite.html