Astroid 2005 YU55 - Fly By 8 Nov 2011
Have you seen this post about asteroid 1999AN10? http://www.cyberspaceorbit.com/an10x.htm The OP says that when the news first appeared that the scientist said the asteroid would hit the earth. Then the same scientist said he made a mistake and retracted his statement. Then all the AN10 stuff disappeared off the net for a while, including NASA's database. When it came back, the new trajectory missed earth, and NASA says there was no possibility of a strike in 2027, even though its orbit is highly chaotic and may even miss the earth as far out as the moon's orbit. When you look at the NASA animation http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=1999 AN10;orb=1 for 7 Aug 2027 and scroll through Aug 7th using the hour button to get the minimum earth distance, it goes down to .0036 AU (about 538,000 KM from the earth's CENTER) even by NASA's calculation, and it stays there at .0036 AU for 3 hours, which is impossible. When it gets that close to the earth, its Earth Distance is changing the fastest of any time in its orbit, not the slowest. That calculation is lying, but why? It is lying probably because the real numbers show that it impacts the earth. This is a good day to watch: 7 Aug 27.
Calculations on the Minor Planet Center web site show a miss distance of .0026 AU (about 389,000 km). http://www.minorplanetcenter.net/mpec/J99/J99N21.html. From what I read about the observations, there is quite a bit of uncertainty on the orbit calculations since they were not sure of the start and stop locations of the orbit streak since it was very faint. Some of the more recent material (http://neo.jpl.nasa.gov/news/news018.html) says the miss distance will be closer with the most likely miss distance of 200,000 km and the minimum possible miss distance of 37,000 KM. There are three "keyholes" that could perturb the orbit enough to strike the earth in 2034, 2044, or 2046, or the orbit change enough from unknown encounters that it could strike the earth in 2027.