Even if status quo tracking goals were met they aren’t sufficient
NATIONAL RESEARCH COUNCIL 2010 - Committee to Review Near-Earth-Object Surveys and Hazard Mitigation Strategies Space Studies Board (“ Survey and Detection of Near-Earth Objects ” pg. 30, Aeronautics and Space Engineering Board Division on Engineering and Physical Sciences, http://www.nap.edu/openbook.php?record_id=12842&page=30)
Thus, assessing the completeness of the NEO surveys is subject to uncertainties: Some groups of NEOs are particularly difficult to detect. Asteroids and comets are continually lost from the NEO population because they impact the Sun or a planet, or because they are ejected from the solar system. Some asteroids have collisions that change their sizes or orbits. New objects are introduced into the NEO population from more distant reservoirs over hundreds of thousands to millions of years. The undiscovered NEOs could include large objects like 2009 HC82 as well as objects that will be discovered only months or less before Earth impact (“imminent impactors”). Hence, even though 85 percent of NEOs larger than 1 kilometer in diameter might already have been discovered, and eventually more than 90 percent of NEOs larger than 140 meters in diameter will be discovered, NEO surveys should nevertheless continue, because objects not yet discovered pose a statistical risk: Humanity must be constantly vigilant. Finding: Despite progress toward or completion of any survey of near-Earth objects, it is impossible to identify all of these objects because objects’ orbits can change, for example due to collisions. Recommendation: Once a near-Earth object survey has reached its mandated goal, the search for NEOs should not stop. Searching should continue to identify as many of the remaining objects and objects newly injected into the NEO population as possible, especially imminent impactors.
SCIENCE FAIR 2010 (1/22, Micelle Kessler, USA Today Social Media Editor, “NASA will miss Congressional deadline for asteroid tracking”, http://content.usatoday.com/communities/sciencefair/post/2010/01/620008263/1)//DT
NASA won't meet Congressional orders to track most city-smashing-sized asteroids in Earth's neighborhood by 2020, an expert panel concluded Friday, because the government didn't provide the money to detect such Near-Earth Objects. In the National Research Council Report, "Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies", the panel finds the 2005 order to find 90% of Earth-threatening asteroids 460 feet or larger infeasible, "because for the past 5 years the administration requested no funds, and the Congress appropriated none, for this purpose." If Congress wants the survey completed by 2022, NASA should launch twin space probes to the orbit of Venus to look back at Earth neighborhood, the study finds. The cheaper option would fund telescopes and complete the 90% goal around 2030. Right now, the federal government spends about $4 million a year to detect asteroids. More research should be done on asteroids, the report argues, particularly since some recent studies suggest impacts from objects as small as 100 feet wide would wipe out a city-sized area. "Somebody needs to decide who is in charge," says astronomer Michael A'Hearn of the University of Maryland in College Park, who led the report panel's committee on diverting asteroids. "No method for diverting asteroids has been experimentally demonstrated," he says. Options include a "gravity tractor" orbiting slow-moving objects and tugging them off course with tidal tugs, a "kinetic" impact of a heavy spacecraft into an asteroid, or a nuclear explosion, "only for the really big and really late discoveries," A'Hearn says. International accords for handling an incoming asteroid don't exist either, he notes. "If you try and divert an asteroid and miss, you might end up landing it on someone else," he says. "The larger question is whether the remaining hazard from impacts is worth a 'crash program' to shorten that time, which implies space missions costing hundreds of millions, typically," says asteroid expert Alan Harris of the Space Science Institute in La Canada, Calif. "First, and most simply, my answer is no, it's not worth it, solely for impact risk reduction." Getting a space mission approved by Congress would likely take until about 2030, he suggests, making it pointless to argue for one." However continuing the existing surveys in concert with other astronomical work seems worthwhile, Harris says, "in a sense, the asteroid survey is like a whole-life insurance policy. Even if you don't find a killer asteroid out there, you reap a tremendous scientific reward at the end of the 'policy period'." "It doesn't surprise me that we can't yet address these questions -- there is yet to be a Congressionally directed research dollar toward the asteroid hazard. Everything to date has been on a shoe string, piggy-backed on other programs," says astronomer Richard Binzel of the Massachusetts Institute of Technology. The NRC report endorses continuing work at facilities such as the 1,000-foot-wide Arecibo radar astronomy facility in Puerto Rico, which is threatened with closure. However, A'Hearn notes the asteroid detection and characterization work at Arecibo can't be completed on the funds devoted to such work, and relies on other astronomical research covering some of the costs of the mammoth facility. "If other research shuts down at Arecibo, the (asteroid detection) share goes up substantially," he says.
Current technology isn’t able to effectively respond to an asteroid
BRADLEY et al 2010 (Los Alamos Research Laboratory, “Challenges of Deflecting an Asteroid or Comet Nucleus with a Nuclear Burst”, http://www.astrosociology.org/Library/PDF/SPESIF2010_Bradley-etal_DeflectingAsteroids.pdf)//DT
Although we have come a long ways since the Tunguska event of June 30, 1908, there is still much we do not know. Even when finished, planned surveys will still not be complete for objects smaller than 140 meters. Such an asteroid or comet nucleus would be large enough to wipe out an area from New York City to Washington, D.C. Objects smaller than about 140 meters will be difficult to detect with much advance warning simply because they are extremely faint except when they are close to Earth. Although we sent probes to several asteroids and comets, we only have detailed information for a few. We also do not have detailed knowledge of the internal structure of asteroids, especially ones of order 10 to 1000 meters in diameter. An asteroid’s response to an impulsive energy burst --- whether it be high explosives, kinetic energy impactor, or nuclear burst --- will be sensitive to both the composition (ice, rock, rock/ice, or iron) and structure (monolithic piece, fractured, or rubble pile) of the body. While we may be able to determine at least the surface composition of a PHO in advance, we may not be able to determine the internal structure in advance. Any mitigation strategy must account for this uncertainty.