Asteroid 2055 YU55 Closed to The Earth

2005 YU55, also written as 2005 YU55, is a potentially hazardous asteroid that is 400 meters in diameter.It was discovered on 28 December 2005 by Robert S. McMillan at Steward Observatory, Kitt Peak.The 2011 approach is the closest known by an asteroid with an absolute magnitude this bright since 2010 XC15 (H = 21.4) approached within 0.5 lunar distances in 1976.

Impact risk assessment

In February 2010 it was rated 1 on the Torino Scale, indicating that a pass near the Earth is predicted that poses no unusual level of danger. On 19 April 2010, highly accurate radar targeting by the Arecibo radio telescope reduced uncertainties about the orbit by 50 percent.This improvement eliminated any possibility of an impact with the Earth for the next 100 years.It was removed from the Sentry Risk Table on 22 April 2010 and and as such it now has a rating of 0 on the Torino Scale.

On 8 November 2011 at 23:28 UT, the asteroid will safely pass within 0.85 lunar distances of the Earth. A lunar distance of 0.85 is also 0.00217 AU (325,000 km; 202,000 mi).On 9 November 2011 at 07:13 UT, the asteroid will pass 0.00160 AU (239,000 km; 149,000 mi) from the moon.During the close approach, the asteroid should reach about apparent magnitude 11, and may be visible to expert observers using high-end binoculars with an objective lens of 80mm or larger. Since the gibbous moon will interfere with the viewing, amateur observers trying to visually locate the asteroid will require a telescope with an aperture of 6 inches (15 centimeters) or larger.

The next time a known asteroid this large will come this close to Earth will be in 2028 when (153814) 2001 WN5 passes 0.00166 AU (248,000 km; 154,000 mi) from the Earth.

Future trajectory

On 19 January 2029, 2005 YU55 will pass about 0.0019 AU (280,000 km; 180,000 mi) from Venus. The close approach to Venus in 2029 will determine how close the asteroid will pass the Earth in 2041. The uncertainties in the post-2029 trajectory will cause the asteroid to pass anywhere from 0.002 AU (300,000 km; 190,000 mi) and 0.3 AU from the Earth in 2041.Radar astrometry in November 2011 should clarify the Earth encounter situation in 2041 and bey