- The Washington Times - Saturday, September 6, 2003

Earlier this month, British astronomers announced that they had detected a Near Earth Object (NEO) named QQ47 large enough to cause a global catastrophe in the extremely unlikely event that it actually encounters the Earth.

While QQ47 has only about a one in one-million chance of impacting the Earth in 2014, its size of about three-quarters of a mile wide makes it a potential civilization killer. An NEO with its girth is large enough to destroy an area the size of Europe and disrupt the global climate. A paper by Andrea Milani, which was published in June in the journal Science, compared the energy released by the impact of a 1-kilometer NEO to that of a global nuclear war.

Astronomers believe there are between 900 and 1,230 NEOs of that size, over half of which have already been discovered by NASA’s Spaceguard Survey. That survey is expected to have identified about 90 percent of large NEOs by 2008. To date, it has only discovered one NEO with a greater-than-minuscule chance of causing a disaster — 1950 DA, which is estimated to have about a 1 in 300 chance of encountering the Earth in 2880. Those estimations are still somewhat uncertain.

Moreover, large NEOs like QQ47 are merely the highest-consequence NEO threat. It is believed that there are about 25,000 midsized NEOs of about 150 meters in diameter, which are large enough to wipe out states or counties. Only about 300 of them have been identified, and up to 250 could be potential threats.

No federal program for deflecting an NEO strike exists, although a few studies have been done. One of the more popular ideas is using the sun’s power to push threatening NEOs out of the way, such as by coating them with reflective paint or covering them with solar panels. Other possibilities to provide the requisite push include attaching rockets to them or exploding nuclear weapons nearby. However, most of those approaches would take years, and nuclear weapons might break NEOs up into smaller, yet still devastating fragments.

About two months ago, a distinguished group of space experts — including Carolyn Shoemaker, David Levy and Freeman Dyson — sent an open letter to members of Congress and the Bush administration calling for additional federal action to address the NEO threat (visit congressneoaction.org). They requested an increase in funding for NEO detection, an expanded NEO exploration program and an initiation of contingency planning for an NEO strike, both to deflect the incoming object and to deal with the consequences of the strike.

Citing NASA’s seeming reluctance to extend the Spaceguard Survey to smaller objects and the silence of military organizations on methods of NEO detection (U.S. spy satellites have recorded the impacts of many small NEOs), Mr. Milani called on the international scientific community to take a more active hand in searching for the objects.

Scientists should help, but the NEO threat also requires additional congressional attention and action, especially since the likelihood of such an encounter increases over time. The government should continue to take prudent, relatively low-cost steps to either avert such eventualities, or at least reduce their potential damage.



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