UK observers were unable to witness for themselves the close-pass of near-Earth asteroid 2005 YU55 on the night of 2011 November 8/9 owing to the country being entirely covered by impenetrable cloud as can be seen in the weather satellite images taken at the time.

UK Cloud on November 8-9

‘YU55′ is especially noteworthy in that it is the largest known NEO to have passed so close to the Earth (0.85 lunar-distances away) that has been predicted in advance of the event. Detailed radar images including animations showing the object rotating will be released by NASA during the next few days, news of which can be found at:
http://www.jpl.nasa.gov/news/index.cfm

Given the poor weather in the UK, BAA member Martin Mobberley used a remotely-operated 0.5-m telescope at the GRAS facilities in New Mexico to secure a 1-minute exposure of the 11th magnitude object taken some 7 hours after closest approach. The very fast moving object is clearly visible as a bright streak in the centre of Martin’s image taken whilst it was at a distance of about 450,000 km from the Earth, just beyond the orbit of the Moon.

2005 YU55 on 2011 November 9th at 06:38 UT – Martin Mobberley

Richard Miles
Director, Asteroids and Remote Planets Section