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Abstract
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In 2005 NASA was tasked by the U.S. Congress to provide a report discussing near-Earth objects (NEOs) in the context of their threat to the Earth. The report was to address various alternatives for a sky survey for NEOs, a recommended option and proposed budget to carry out the sky survey, and an analysis of possible alternatives for diverting an object on a likely collision course with Earth.
Due to the large number and distribution of asteroids and comets in the solar system, there is the distinct possibility of one of them striking Earth just as comet Shoemaker-Levy 9 struck Jupiter. A debate is ongoing in the scientific community as to how best to divert such a threat. In 2005 NASA was directed by Congress to provide a report on the detection of near-Earth objects (NEOs) and their mitigation if determined to be a threat. The report was delivered in March 2007; as input to that report, the work reported here provided information on conventional methods to divert a potentially hazardous object (PHO) including conventional explosives and direct impact with a rocket. Other slow push conventional approaches include propulsion systems attached to the asteroid or comet and the recently proposed gravitational tractor. Advantages of conventional explosives are that they can be delivered in small packages so that the asteroid or comet is in no danger of being broken up and it is possible to accurately compute the momentum transferred to the asteroid or comet through modern validated numerical techniques. This work demonstrates that conventional explosives can be an efficient conventional method to divert an asteroid or comet and computes the amounts of explosives needed. |