asteroid 2004 MN4

A quarter of a mile (400 meters) wide and large enough to cause considerable damage, asteroid 2004 MN4 was the first asteroid in history to be ranked 4 on the Torino Scale, a measuring tool like the Richter Scale that measures the threat of space rocks. On December 23, 2004, scientists reported that this giant space rock had an outside chance of hitting the earth on April 13, 2029. Four days later, researchers said that the odds could be as high as 1 in 37 (2.7 percent). On December 29, 2004, NASA specialists who had studied old observations of MN4 announced that they had ruled out the possibility of an earth impact on April 13, 2029. The threat, however, was not immediately reduced to zero.

Last updated: December 30, 2004.