Today the B612 Foundation issued a call to action to the United States Government. In a detailed presentation, members of this scientific organization stated:
The purpose of this paper is to call upon the Congress of the United States to initiate, via the National Research Council or other appropriate body, a formal analysis of the circumstances presented by the close encounter between the Earth and asteroid 2004MN4 in April 2029, and the potential for a subsequent collision with Earth in 2036.
This is not science fiction, and although the paper clearly states that the chances for impact are slight (1 in 10,000 based on limited data) there is enough uncertainty of data to suggest that the best course of action today is to initiate a NASA mission to attach a radio transponder to this asteroid by 2014. This will allow scientists to determine the asteroid's precise orbit over the next nine years, in time to take action if the likelihood of impact drops to between 1 in 100 and 1 in 10, based on the new observational data. "Action" means a NASA mission to deflect the asteroid enough to cause it to miss Earth by a wide margin. It's easier to do this sooner, and very difficult (near impossible) to do at the last minute.
This asteroid, estimated by NASA's Jet Propulsion Laboratory (JPL) to be 320 meters in diameter, will come within 30,000 km. of the Earth, passing just behind the Earth in its orbit but well within the geostationary satellite orbit. A collision with the Earth during this 2029 close encounter has been definitively ruled out. Observers in Europe and North Africa, however, will be treated to an unusual sight; the opportunity to view an asteroid with the unaided eye as it passes through the early evening sky toward the just set Sun.