Big asteroid has big dent.The asteroid called 4 Vesta has long had a special place in the hearts of planetary scientists. Spectra of this rock, the third largest asteroid, have revealed that it is the only known parent of a class of meteorites Meteorites See also astronomy. aerolithology the science of aerolites, whether meteoric stones or meteorites. Also called aerolitics. astrolithology the study of meteorites. Also called meteoritics. called basaltic ba·salt n. 1. A hard, dense, dark volcanic rock composed chiefly of plagioclase, pyroxene, and olivine, and often having a glassy appearance. 2. A kind of hard unglazed pottery. achondrites. This class accounts for 6 percent of all meteorites that fall to Earth. Because of its placement in the asteroid belt, Vesta can't deliver its fragments to Earth directly. However, a string of small, Vesta-like asteroids This is a list of numbered minor planets, nearly all of them asteroids, in sequential order. As of late September 2007 there are 164,612 numbered minor planets, and many more not yet numbered. Most asteroids are ordinary and not particularly noteworthy. is at the right location to do so (SN: 10/24/92, p. 286). Scientists had assumed that these bodies represent pieces of Vesta knocked off during some past collision, but it remained unclear whether the large asteroid had, in fact, ever suffered a mammoth impact. An analysis of 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. images of Vesta taken last year, when the rocky body was the closest it had been to Earth in a decade, now reveals a crater 460 kilometers wide and 13 km deep near the asteroid's south pole South Pole, southern end of the earth's axis, lat. 90° S. It is distinguished from the south magnetic pole. The South Pole was reached by Roald Amundsen, a Norwegian explorer, in 1911. See Antarctica. . Potato-shaped Vesta has an average diameter only slightly bigger, 530 km. The collision gouged I percent of the asteroid's volume, enough material to account easily for the family of small, Vesta--like asteroids, Peter C. Thomas of Cornell University and his colleagues report in the Sept. 5 Science. |
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