As mentioned in one of our previous articles, Asteroid Viewing Tuesday Nov 8, 2011 6:30 P.M. Citrus County FL, the Asteroid YU55 will be passing within 202,000 from earth, between the orbit of the earth and moon. It will be the nearest flyby of an asteroid of this size since 1976. YU55 is the size of a city block and will be passing through the night sky the evening of Nov. 8, 2011, at 6:28 P.M. EST, the sky chart below will assist you in spotting this rare occurrence, if all the extraneous elements are favorable. You’ll need a clear sky, probably a good telescope away from town lights, and good luck. Search for the 12th brightest star of the evening, Altair, it should be in Northeast, with the Moon on the West, and wait for YU55.
Archive for the ‘YU55 to Approach Earth on November 8, 2011’ Category
Don Yeomans, Lance Benner and Jon Giorgini REST OF STORY HERE…
Trajectory of Asteroid 2005 YU55 – November 8-9, 2011
Click on image for animation
Near-Earth asteroid 2005 YU55 will pass within 0.85 lunar distances from the Earth on November 8, 2011. The upcoming close approach by this relatively large 400 meter-sized, C-type asteroid presents an excellent opportunity for synergistic ground-based observations including optical, near infrared and radar data. The attached animated illustration shows the Earth and moon flyby geometry for November 8th and 9th when the object will reach a visual brightness of 11th magnitude and should be easily visible to observers in the northern and southern hemispheres. The closest approach to Earth and the Moon will be respectively 0.00217 AU and 0.00160 AU on 2011 November 8 at 23:28 and November 9 at 07:13 UT.
Discovered December 28, 2005 by Robert McMillan of the Spacewatch Program near Tucson Arizona, the object has been previously observed by Mike Nolan, Ellen Howell and colleagues with the Arecibo radar on April 19-21, 2010 and shown to be a very dark, nearly spherical object 400 meters in diameter. Because of its approximate 20-hour rotation period, ideal radar observations should include tracks that are 8 hours or longer on multiple dates at Goldstone (November 3-11) and when the object enters Arecibo’s observing window on November 8th.
Since the asteroid will approach the Earth from the sunward direction, it will be a daylight object until the time of closest approach. The best time for new ground-based optical and infrared observations will be late in the day on November 8, after 21:00 hours UT from the eastern Atlantic and western Africa zone. A few hours after its close Earth approach, it will become generally accessible for optical and near-IR observations but will provide a challenging target because of its rapid motion across the sky.
Although classified as a potentially hazardous object, 2005 YU55 poses no threat of an Earth collision over at least the next 100 years. However, this will be the closest approach to date by an object this large that we know about in advance and an event of this type will not happen again until 2028 when asteroid (153814) 2001 WN5 will pass to within 0.6 lunar distances. REST OF STORY HERE!