Near-Earth Object Surveys and Hazard Mitigation Strategies: Interim Report
The United States is currently the only country with an active, government-sponsored effort to detect and track potentially hazardous near-Earth objects (NEOs). At congressional direction, NASA funds several ground-based observatories primarily dedicated to conducting NEO surveys. Several new or proposed observatories with other non-NEO objectives can also contribute to the NEO survey task. Congress has mandated that NASA detect1 and track 90 percent of NEOs that are 1 kilometer in diameter or larger. These objects represent a great potential hazard to life on Earth and could cause global destruction. NASA is close to accomplishing this goal. Congress has more recently mandated that by 2020 NASA should detect and track 90 percent of NEOs that are 140 meters in diameter or larger, a category of objects that is generally recognized to represent a very significant threat to life on Earth if they strike in or near urban areas. Achieving this goal may require the building of one or more additional observatories, possibly including a space-based observatory.
Congress directed NASA to ask the National Research Council to review NASA’s near-Earth object programs. This interim report addresses some of the issues associated with the survey and detection of NEOs. However, the committee continues its information collection and deliberations and will address a broader range of issues in its final report, due for delivery at the end of 2009. During its study so far, the committee has determined that the issues of survey and detection and characterization2 and mitigation are closely linked and should be addressed as a whole. For example, NEOs detected by ground-based telescopes can be better tracked by the Arecibo Observatory when within its range. Thus this observatory plays a key role in determining physical characteristics of NEOs, important in determining how to mitigate the effects of NEOs on Earth. In part because of this interrelationship, and because the interim report does not address mitigation issues, the committee has deferred proposing an optimum approach to the survey and detection problem until its final report. The final report will contain findings and recommendations for survey and detection, characterization, and mitigation of near-Earth objects based on an integrated assessment of the problem.
