The way a comet crumbles.For a comet, breaking up is not so hard to do. A comet called 73P/Schwassmann-Wachmann 3 has been disintegrating for years, but the pace has picked up in recent weeks. The comet has already broken into at least 59 pieces. As it gets closer to the sun, scientists are expecting it to crumble crum·ble v. crum·bled, crum·bling, crum·bles v.tr. To break into small fragments or particles. v.intr. 1. To fall into small fragments or particles; disintegrate. even more. Comets Non-periodic comets are seen only once. They are usually on near-parabolic orbits that will not return to the vicinity of the Sun for thousands of years, if ever. Periodic comets usually have elongated elliptical orbits, and usually return to the vicinity of the Sun after a number are giant, fragile balls of ice and dust that take odd orbits around the sun. Sometimes, they're really far away from the sun. Sometimes, they're really close. When a comet is near the sun, some of its ice melts, which produces its distinctive tail. Comet 73P/Schwassmann-Wachmann 3 orbits the sun every 5.4 years. Over the past month, the Hubble Space Telescope Hubble Space Telescope (HST), the first large optical orbiting observatory. Built from 1978 to 1990 at a cost of $1.5 billion, the HST (named for astronomer E. P. Hubble) was expected to provide the clearest view yet obtained of the universe. and other instruments have watched the comet's biggest 36 chunks break up into dozens of smaller bits. These pieces measure between 20 and 30 meters (66 to 98 feet) across. The breakup breakup The division of a company into separate parts. The most famous breakup to date was the 1984 division of AT&T (formerly, American Telephone & Telegraph Company). This breakup was intended to increase competition in the communications industry. shows that the cores of comets "are as fragile as the meringue in lemon-meringue pie," says Casey Lisse of the Johns Hopkins Noun 1. Johns Hopkins - United States financier and philanthropist who left money to found the university and hospital that bear his name in Baltimore (1795-1873) Hopkins 2. Applied Physics Laboratory The Johns Hopkins University Applied Physics Laboratory (APL), located in Laurel, Maryland, is a not-for-profit, university-affiliated research center employing 4,000 people. in Laurel, Md. Images from the Spitzer Space Telescope Spitzer Space Telescope: see infrared astronomy; observatory, orbiting. show lots of tiny specks of dust between the comet chunks. One theory is that comets lose material mostly by releasing millimeter-size dust particles. Analyses of some of the larger chunks reveal details about how the comet is falling apart. "The breakup has cracked the comet open like an egg," revealing its interior composition, says Cincinnati-based Spitzer scientist Michael Sitko of the Space Science Institute. 73P/Schwassmann-Wachmann 3 will be closest to the sun on June 6. As it approaches, however, Hubble images show that some of the chunks are actually moving in the opposite direction. Heat from the sun may be the cause. In mid-May, chunks of 73P/Schwassmann-Wachmann 3 will get within 11.7 million kilometers (7.3 million miles) of Earth. That's the closest any comet has come to our planet in 20 years. http://www.sciencenewsforkids.org/articles/20060510/Note3.asp From Science News for Kids May 10, 2006. Copyright [C] 2006 Science Service. All rights reserved. |
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