Old news, but worth posting about:
CSMonitor: Asteroid headed our way:
>NASA researchers have begun considering whether the US needs to tag the asteroid, known as 99942 Apophis, with a radio beacon before 2013. Timing is everything, astronomers say. If officials attempt to divert the asteroid before 2029, they need to nudge the space rock’s position by roughly half a mile – something well within the range of existing technology. After 2029, they would need to shove the asteroid by a distance as least as large as Earth’s diameter. That feat would tax humanity’s current capabilities.
Actually that was the first I heard about it; unless I read about it before it was officially named. I check on this stuff all the time. Here’s what I found:
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99942 Apophis is a Near-Earth asteroid that caused a brief period of concern in December 2004 because initial observations indicated a relatively large probability that it would strike the Earth in 2029. However, additional observations provided improved predictions that essentially eliminated the possibility of an impact on Earth or the Moon in 2029, although future impacts are still possible.
When first discovered, the object received the provisional designation 2004 MN4 (sometimes written 2004 MN4), and news and scientific articles about it referred to it by that name. When its orbit was sufficiently well calculated it received the permanent number 99942 (on June 24, 2005), the first ever numbered asteroid with Earth impact solutions. Receiving a permanent number made it eligible for naming, and it promptly received the name “Apophis” as of July 19, 2005. Apophis is the Greek name of the Ancient Egyptian god Apep, “the Destroyer”, who dwells in the eternal darkness of the Duat (underworld) and tries to destroy the Sun during its nightly passage.
Apophis is expected to come close enough that on April 13, 2029 (Friday the 13th) it will become as bright as magnitude 3.3 (easily visible to the naked eye). This close approach will be visible from Europe, Africa, and western Asia. Throughout recorded history, no other closely approaching objects of this size have been visible to the naked eye. As a result of its close passage, it will move from the Aten (see below) to the Apollo class.
Apophis remains at level one on the Torino scale because of very low but non-zero probability of impact on approaches in 2035, 2036 and 2037. However, the approach in 2029 will substantially alter the object’s orbit, making predictions uncertain without more data. “If we get radar ranging in 2013 [the next good opportunity], we should be able to predict the location of 2004 MN4 out to at least 2070.” said Jon Giorgini of JPL [1].
Source: http://en.wikipedia.org/wiki/2004_MN4