From: House Committee on Science, Space, and Technology
Posted: Thursday, October 3, 2002
WASHINGTON, D.C. - Scientists are making progress in cataloguing and tracking large near-earth objects (NEOs), but a serious threat still remains from smaller objects, an expert panel told the Space and Aeronautics Subcommittee today.
These smaller asteroids (200-500 meters wide) could potentially demolish a city with a direct hit or cause a tsunami capable of wiping out entire coastal areas if they land in the ocean. NASA has catalogued nearly 50 percent of asteroids 1 kilometer wide and larger. Astronomers estimate that between 900 and 1300 of the larger asteroids exist while there could be as many as 50,000 in the smaller range.
Subcommittee Chairman Dana Rohrabacher (R-CA) stated, "The threat posed by incoming asteroids and comets is a serious, potentially life-threatening topic. Given the number of near-earth objects in space, it is a matter of time before we are faced with an event unparalleled in human history. I hope that my legislation, H.R. 5303, passed by the House on Tuesday will strengthen existing government capabilities for tracking natural space objects by encouraging private citizens to observe asteroids and comets."
Subcommittee Ranking Member Bart Gordon (D-TN) added, "NASA's Mission Statement says that part of its mission is '...to protect our home planet.' I hope NASA will heed the message of today's hearing and work with other agencies of the U.S. government to craft a timely, cost-effective plan to detect and catalog as many as possible of the Near-Earth asteroids and comets that could potentially threaten our population. We cannot afford to be complacent."
Dr. David Morrison, senior scientist at the NASA Ames Research Center, discussed NASA's goals and accomplishments in monitoring NEOs through the "Spaceguard" program. Morrison noted that Spaceguard was halfway to its goal and he expected that by 2008 NASA will have 90 percent of large, kilometer-sized threatening asteroids catalogued. Morrison added, "Our objective should be to find a large impactor far in advance, and thus provide decision-makers with options for dealing with the threat and defending our planet from cosmic catastrophe."
NEOs also pose a serious concern for the military, Brigadier General Simon P. Worden testified. Worden told of an asteroid that entered the atmosphere and exploded above the Mediterranean during last year's India-Pakistan conflict. U.S. satellites detected an energy release and shockwave comparable to the Hiroshima bomb, and Worden explained that had the event taken place at the same latitude two hours earlier and mistaken for a nuclear detonation it could have had devastating consequences. Worden added, "I believe there is considerable synergy between national security requirements related to man-made satellites and global security requirements related to NEO impacts."
Witnesses also debated the merits of continuing the cataloging effort on smaller NEO's once the Spaceguard program is completed. Dr. Brian Marsden, Director of the Minor Planet Center of the Smithsonian Astrophysical Observatory, testified that handling the large amount of data from surveys of smaller NEOs would be a challenging, but feasible, task. Dr. Joseph Burns, a member of the Solar System Exploration Survey Committee of the National Research Council, testified that NASA should partner with the National Science Foundation to build and operate a large ground-based survey telescope because of NSF's expertise in ground based astronomy and NASA's traditional support of ground-based solar system observations that support space missions.
Dr. Ed Weiler, NASA Associate Administrator for Space Science, disagreed saying, "I feel that it is premature to consider an extension of our current national program to include a complete search for smaller-sized NEOs." He also noted that NASA did not feel the agency "should play a role in any follow-on search and cataloging effort unless that effort needs to be specifically space-based in nature."
Rep. Anthony Weiner (D-NY) said, "For too long we've assumed that the worst asteroid risk would come from Hollywood-in the form of a sequel to flops like Deep Impact or Armageddon. But the threat posed by Near Earth Objects is real, and if we can plow $100 million into a summer flick, we can certainly give NASA the means to make us safer from real life blockbusters."
Witness testimony and an archived web cast of the proceedings can be found at www.house.gov/science <http://www.house.gov/science>.
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