No, that was a song by the Beatles. I had better say: When I'm 84 (and if I am still around, ...)
Alan MacRobert (2005) Asteroid 2004 MN4: A Really Near Miss (Sky & Telescope, May 2005, pp. 16-17): This big an asteroid should whiz this close by Earth only once in 1,300 years. If you expect to be alive on April 13, 2029, you can look forward to an asteroid- watching party across three continents like nothing the world has ever seen. In late January, Lance Benner (Jet Propulsion Laboratory) and three other radar astronomers used the giant Arecibo dish in Puerto Rico to ping the near-Earth asteroid 2004 MN4 and refine its orbit. This object briefly made headlines last December when astronomers estimated that it had a 1-in-38 chance of hitting Earth in 2029. The threat quickly passed when old images were found that pinned down the asteroid's orbit well enough to guarantee that it will miss us (see last month's issue, page 20). The radar measurements confirm that the asteroid will miss Earth - but by only about half the distance calculated before. As a result, we're going to get a once-in-a-millennium naked-eye asteroid show. Paul Chodas, Steve Chesley, Jon Giorgini, and Don Yeomans of NASA's Near Earth Object Program find that the asteroid will pass 4.7 Earth radii (30,000 kilometers, or 18,600 miles) from Earth's surface. It should brighten to magnitude 3.3, similar to the faint- est star of the Big Dipper, while moving northwest across Sextans and Cancer at a speed reaching 42� per hour. Europe, Africa, and Asia will have ringside seats. With a newly estimated diameter of 320 meters (1,050 feet), 2004 MN4 will appear up to 2 arcseconds wide, making it barely resolvable in amateur telescopes. Skywatchers in North and South America will get their best view hours earlier, while the asteroid is still on its approach and only 7th magnitude. Best regards, Bernd ______________________________________________ Meteorite-list mailing list [email protected] http://six.pairlist.net/mailman/listinfo/meteorite-list
