Giant asteroid to pass near Earth
It poses no danger to the Earth and it will be invisible to the naked eye.
Asteroid 2005 YU55's closest approach, at a distance of 325,000km (202,000mi), will be at 2328GMT. It is the closest the asteroid has been in 200 years.
It is also the largest space rock fly-by the Earth has seen since 1976; the next visit by such a large asteroid will be in 2028.
The aircraft-carrier-sized asteroid is incredibly darkly coloured in visible wavelengths and nearly spherical, lazily spinning about once every 20 hours as it races through our neighbourhood of the Solar System.
It will trace a path across the whole sky through to Thursday.
"This is the closest approach by an asteroid that large that we've ever known about in advance," said Lance Benner of Nasa's Jet Propulsion Laboratory.
But he stressed that there was no chance that the pass would be anything other than a close encounter.
"2005 YU55 cannot hit Earth, at least over the interval that we can compute the motion reliably - which extends for several hundred years," he said.
Instead, the pass gives astronomers a rare opportunity to study the asteroid in detail; Kazinform cites BBC.
To learn more go to www.bbc.co.uk
