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: http://www.naic.edu/news_newadmin/asteroid2005yu55_a.html
Дата изменения: Mon Nov 7 19:27:48 2011 Дата индексирования: Mon Oct 1 23:49:13 2012 Кодировка: Поисковые слова: regolith |
ASTEROID 2005 YU55 Asteroid 2005 YU55 was listed on NASA's "Sentry Risk Page" as having as small (about one in 10 million) chance of hitting the Earth in the next century. We observed this asteroid with the Arecibo Planetary Radar system on April 19-23 2010.
Previous to April 2010, several hundred optical observations over 5 years had identified potential Earth impacts. A few Arecibo radar measurements over two days showed that no impacts would occur. A very close pass by Earth will take place November 8, 2011. These observations in 2010 measured the distance to the asteroid at a resolution of 7.5 meters, about 25 feet, when it was over a million miles away. The observations on November 8 2011 will also measure the distance to within 25 feet, but the asteroid will only be 205,000 miles away, about an hour and a half before its closest approach to the Earth. The object poses no hazard to the Earth through at least 2041. Dr. Michael C. Nolan - Arecibo Observatory -------------------------------------------------------------------------------------------ASTEROID FLYBY: NASA radars are monitoring 2005 YU55, an asteroid the size of an aircraft carrier, as it heads for a Nov. 8th flyby of the Earth-Moon system. There is no danger to our planet. At closest approach on Tuesday at 3:28 pm PST (23:28 UT), the space rock will be 324,600 kilometers away. Nevertheless, professional astronomers are eagerly anticipating the flyby as the asteroid presents an exceptionally strong radar target.б Even amateur astronomers might be able to photograph it during the hours around closest approach.б Check http://spaceweather.com for observing tips and more information.
Astronomers used the planetary radar system at the Arecibo Observatory radio telescope to spot the asteroid, called 2005 YU55, over four days starting on April 19.
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