Earth May Attract Asteroid Enough to Make a Big Impact

Asteroid 2004 MN4, which was once a 1 in 38 risk to hit Earth, may hit Earth after all some astronomers fear. When the asteroid was first spotted, there was a slight chance in would hit the Earth on April 13, 2029, coincidently, Friday the 13th. As more data came in and a more precise orbit could be calculated, the odds continued to increase until finally additional data refined the orbit enough to be sure the asteroid would pose a threat. The closest approaches are now calculated to be in 2034 and 2035.

However, the close pass by Earth in 2029 will alter the asteroid’s orbit. Because its mass and the distance at which it will pass by Earth is not exactly known, the change in its orbit is unknown and this has some astronomers concerned.
A NASA press release from Feb. 3, 2005 states:

The passage of the asteroid by the Earth in 2029 alters its subsequent trajectory and causes its position uncertainty region to expand rapidly as it moves away from Earth. As a result, the asteroid’s motion is much less predictable after the 2029 close Earth approach.

The danger of an impact in 2034 or 2035 will not be known until it passes by in 2029. Some experts think that the asteroid should be “tagged” with a radio transmitter to broadcast its location so closer tabs can be kept on it’s orbit. One possible opportunity would be in 2012 when the asteroid passes 10 million miles from Earth.

Even if this asteroid doesn’t pose a risk after more data is in, the danger of some asteroid impacting Earth is a real threat and we need to learn how to deal with it. 2004 MN4 can provide an excellent opportunity.

The article was published in the London Times.