ControlFreal writes "Asteroid 2004 MN4 was introduced earlier on Slashdot, and although scientists are now fairly certain that is will miss earth on April 13th, 2029, the modification to its orbit caused by Earth's gravity may still cause an impact one or a couple of orbits further down the road, the Times reports; the impact probabilities in 2035, 2036 of 2037 will not be known until the exact modification to its orbit is known; in 2029, that is. By then it may be too late for effective counter-measures. An impact would cause an energy release equivalent to about 1 Gigaton of TNT (~4e+18 Joule), and while that won't cause a massive extinction event, it causes widespread devastation. More info on 2004 MN4 can be found here and here."

http://science.slashdot.org/article....91230&from=rss