The path of small asteroid 2011 MD past the Earth and the Moon in late June 2011. Courtesy NASA Near Earth Object Program

A small recently discovered asteroid will zoom past the Earth on the evening of Monday 27 June 2011 Australian time. At its closest at about 11 pm AEST it will be 12 000 km above the Earth’s surface. There is no risk whatsoever to anyone on Earth. However, as the asteroid will pass within the ring of geosynchronous satellites, there is an extremely small risk of damage to one of those.

Amateur astronomers with reasonably sized telescopes will be able to see the faint object move fairly rapidly across the sky. They do need, however, very accurately set up telescopes and a good understanding of the right ascension and declination coordinate system. Fortunately, the time to observe the asteroid is before moonrise.

The asteroid will be at its brightest at about 10:15 pm AEST when, as seen from Sydney, it will be just above the constellation Corvus in the western sky. From then on it will be heading downwards and towards the left or south and becoming fainter as the Sun illuminates less of the side that we see. The asteroid will set below the horizon from Sydney just after its closest approach, at about 11:15 pm.

Weather permitting, we look forward to some interesting photos from our amateur astronomer friends.