David Morrison from Nasa writes the following summary of the 2004 Christmas asteroid scare from the Ames Research center.
An Excerpt-pay special attention to the last few lines..
The Near-Earth asteroid (NEA) named 2004 MN4 began to attract the attention of asteroid researchers just before Christmas of 2004. Don Yeomans of JPL summarized the information available on December 22 as follows: 2004 MN4 was discovered on 19 June 2004 by Roy Tucker, David Tholen and Fabrizio Bernardi from Kitt Peak, Arizona, and observed over two nights. On 18 December, the object was rediscovered from Australia by Gordon Garradd of the Siding Spring Survey. Using further observations from around the globe over the next several days, the possibility of impact in 2029 was realized by both the automatic SENTRY system of NASA's NEO Program Office and the similar automatic system at the University of Pisa (NEODyS). The diameter of MN4 was estimated to be about half a kilometer (later revised downward slightly to 400 m). The predicted flyby would take place on April 13, 2029, and the possibility of an impact could not be ruled out..............
.......This case of MN4 was unusual in two ways: for a few days it yielded a value of TS=4, far higher than any encountered previously, and for several days the addition of new data served to increase the calculated odds of impact. However, just like a run of good (or bad) throws of the dice, this trend reversed and the calculated impact probability went to zero. This is, of course, what we expect for any particular NEA. The odds are overwhelming that they will miss us. But if we were just playing the odds, we would not be in this business. We are in it because there is a possibility of the statistical fluke, of finding an asteroid that will hit in our lifetimes. From that perspective, we cannot assume that time will resolve all threats -- even though that is the likely outcome for any particular NEA.
As has been noted numerous times before on this blog, we need to allot more resources to discovering a means in which to deal with mitigating potentially havoc causing impacts. We do spend money on searching the skies for these impactors, but it is paltry next to what is spent on other projects such as the Cassini probe. I am in full support of these other projects, but I still feel that we need to shift priorities towards programs such as the B612 Foundation. They have proposed to attach a magnetoplasma rocket to an asteroid and alter its orbit-here's the rocket-
If we could figure out a way to stop Hurricanes, or mitigate their effects, wouldn't be wise to do so? We don't have all of the technology ready now to deal with an asteroid such as 2004 MN4, but we need to start designing and implementing it now. Because as we get better at detecting asteroids in our solar system, we seem to find more of them as the following graph illustrates.
It would be irresponsible for our generation to knowingly ignore this issue and hope that future generations can generate the needed technology to mitigate asteroids and other impactors. Yes, the odds are slim of it happening in our lifetime, that doesn't mean it won't.