Near Earth Object Program
The National Aeronautics and Space Administration’s Near Earth Object Program coordinates NASA sponsored work to detect, track and catalogue Near Earth Objects, asteroids and comets that could approach Earth near enough to be hazardous.
The NEO Program goal is to locate 90% or more of the asteroids and comets that are larger than 1 kilometer in diameter by the end of 2020. There are an estimated 1,000 such asteroids and comets.
The NEO Program also supports and initiates communications within the community of astronomers and the public in the event that any potentially hazardous objects are discovered.[1]
In the USA, initial attempts at coordinating efforts by the US Government to ascertain threat from NEOs are credited to Representative George E. Brown Jr. who chaired the House Science and Technology Committee in the 1990s. In 1991, Brown initiated Congressional request of NASA to investigate NEO hazards. Following the 1994 impact of Comet Shoemaker-Levy 9 into Jupiter, Brown’s Committee asked NASA to accelerate Program Spaceguard to locate 90% of NEOs larger than 1 kilometer within ten years.[2][3][4][5][6]
Near Earth Object Search Programs
The NEO Search Programs include various groups within NASA and external to track, detect, analyse and catalogue NEOs. Cooperating agencies in other coutnries include Australia, Italy and Japan.
NEO Discovery Teams
Active and planned teams currently work to detect NEOs. Initially photographic comparisons of a region of the sky were made to detect any changes made over a period of time. Using a time frame of minutes, the comparisons were able to discern close moving objects from galaxies and stars which would show no change in position. NEOs would appear to rise above the background when viewed with stereo viewing microscopes.
At the present time, all NEO discovery teams use charged couple devices (CCD) rather than photographs. CCD cameras record images digitally and are more sensitive and accurate than older photographic methods but use a similar method of detection in that several CCD images separated by a few minutes are taken of the same area of sky and are then compared to detect any relative movement. Computer – aided analyses has also replaced the earlier stereo-microscope technique.
Separation of each digitally recorded object and location from one image to the next, the direction of travel and brightness are employed to indicate proximity to Earth, size and orbital characteristics. The greater the change in position on digital images, the greater the proximity of the NEO to Earth since changes in position will show relatively little change in movement over vast distance distances from Earth.
Near-Earth Asteroid Discovery Statistics
NASA Near-Earth Object Search Report
Lincoln Near-Earth Asteroid Research (LINEAR)
Near-Earth Asteroid Tracking (NEAT)
Spacewatch
Lowell Observatory Near-Earth Object Search (LONEOS)
Catalina Sky Survey
Japanese Spaceguard Association (JSGA)
Asiago DLR Asteroid Survey (ADAS)
References
- ↑ What Is The Purpose Of The Near-Earth Object Program? Near Earth Object Program, NASA
- ↑ David Malakoff (1999) U.S. Science Advocate George Brown Dies Science 23 July 1999: Vol. 285. no. 5427, p. 509
- ↑ Congressional Hearings on NEO Survey Programs Asteroid and Comet Impact Hazards, NASA
- ↑ George Brown's view of science and technology in Congress Chemical & Engineering News (1997). American Chemical Society
- ↑ Death of US Congressman George E. Brown Asteroid and Comet Impact Hazards, NASA
- ↑ The NASA/USAF NEO Search Program Asteroid and Comet Impact Hazards, NASA. Details Safeguard Survey
- ↑ Near Earth Object Discovery Teams Near Earth Object Program, NASA
- ↑ Finding them: Near Earth Object Observations, Survey Completeness and Future Needs Yeomans, D. K. (2004) Jet Propulsion Lab and Caltech. NASA NEO Program Office