Asteroid 2012 TC4 is due to pass within 95 000 km of the Earth tonight (Friday 12/Saturday 13 October 2012), which is roughly a quarter of the distance between the Earth and the Moon, which orbits at an average distance of slightly over 384 000 km. The asteroid was only discovered on Tuesday 4 October, by the Panoramic Survey Telescope & Rapid Response System at the University of Hawaii's Institute for Astronomy.
The passage of 2012 TC4 across the night sky; the times given are in North American Central Daylight Time, which is five hours behind GMT. A fairly good telescope would be needed to observe the asteroid, as it will only be a 14th magnitude object at it's brightest (object's with magnitude's greater than 5 are invisible to the naked eye). Astro Bob.
The asteroid is thought to be between 17 and 30 m across, which is far too small to present any danger to people on the ground; such an object would mostly burn up in the atmosphere if it did strike, with only fragmentary remains reaching the ground. 2012 TC 4 is thought to orbit within the plane of the Solar System, in an eccentric orbit that takes it within the Earth's Orbit and outside that of Mars, completing one circuit of the Sun every 531 days.
Diagram showing the orbits of Mercury, Venus, Earth, Mars and 2012 TC4, with their positions on 12 October 2012. Image created using the JPL Small-Body Database Browser.
See also Comet C/2012 S1 (ISON) to pass within 60 000 000 km of the Earth, Asteroid 2002 AM₃₁ flies past the Earth, 2012 LZ1; bigger than we thought, Asteroid 2012 LZ1 flies by the Earth and The origin of Comet P/2006 VW₁₃₉.
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