Recent news about the approach of near Earth object (NEO) Asteroid 2005 YU55 this November 8-9 has brought around speculations of a doomsday scenario. People say it's going to impact Earth, and a lot of fuss is going about in the internet.
Asteroid 2005 YU55 WILL NOT IMPACT EARTH during its approach. The asteroid will miss us by a margin of 325,000 km (200,000 miles), which is 0.85 lunar distances from the Earth. The path of the asteroid doesn't bring it close enough to be pulled by Earth into a collision course.
The C-type asteroid is relatively large, nearly spherical, at 400 meters in diameter. It was discovered in 2005 by Robert McMillan of the Spacewatch program near Tucson, Arizona. This NEO will be the closest approach of an object this big.
However, the approach of 2005 YU55 isn't even gonna be much of a visual sight since it will just appear as 1/4th arcseconds across (moon is 1800 arcsecs, which means you need a telescope to see it) and only with a visual brightness of magnitude 11. Not to mention its closest approach will be during daylight. Only radio telescopes can get high resolution imagery of the asteroid.
So, again there is nothing to worry about. :)