Short Takes.* PLUTO Pluto, in astronomyPluto, in astronomy, a dwarf planet and the first Kuiper belt, or transneptunian, object (see comet) to be discovered (1930) by astronomers. Pluto has an elliptical orbit usually lying beyond that of Neptune. Although Pluto was long regarded as a planet, since the discovery (beginning in 1992) of other Kuiper belt objects, including one with a diameter larger than that of Pluto, astronomers have recognized the need to reclassify Pluto, NOT A PLANET?Poor Pluto has always been the runt The frame that remains after a collision on a CSMA/CD medium such as Ethernet. See runt filtering. of the litter. Of the nine planets in our solar system, it's both the smallest and farthest from the sun. Now some scientists question whether the scrawny ice ball should be considered a planet at all. Last January, astronomers at the Rose Center for Earth and Space at New York's American Museum of Natural History demoted Pluto from planet to comet, a frozen chunk of gas and dust. "Pluto, being half ice by volume, should assume its rightful status as the King of the Comets," says astronomer Neil Tyson. Pluto is about 2,280 kilometers (1,417 miles) wide--smaller than many planets' moons. * ELECT A NATIONAL TREE Though America is home to a vast variety of tree species--maple, oak, birch, buckeye--none has achieved national symbol status, like the national anthem or bird. To honor the importance of U.S. trees, the National Arbor Day Foundation wants you to help elect a national tree. Cast your vote and learn more about American tree types by logging onto www.arbor day.org. Online voting takes place until mid-night April 27, 2001. |
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