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A. W. Harris (Space Science Institute), E. L. G. Bowell (Lowell Observatory)
Present NEO surveys cover essentially all observable sky, about 15,000 square degrees, per month, to a limiting V magnitude of about 19.5. It is projected that this depth of surveying, if continued for a total of ten years (to about 2008) should yield close to 90 population to absolute magnitude H < 18.0, or equivalently, larger than about 1 km diameter. The 8.4 meter aperture LSST should be capable of surveying the same sky area to a limiting V magnitude of about 23.5 or 24. An added complication is that at such faint magnitudes, the LSST will have to do its own follow-up observations to obtain orbits, thus requiring several repeat coverages of the entire sky each month.
The present NEO surveys are discovering enough very small NEAs to allow a statistical estimate of population down to about H = 26.0 (D = 25 m). The LSST survey, penetrating about 4 magnitudes fainter, should provide enough discoveries to estimate the population down to about H = 30.0, or diameters down to about 4 m. This is approximately the size of meteoroid that enters the Earth's atmosphere about once per year, as detected by military satellite monitors. Thus it should be possible to relate these IR detections to the optically observed NEA population. In the larger size range, it is expected that a 10-year LSST survey will discover about 90 diameter, and about half of those down to 100 m diameter, which is near the limit of the smallest objects that can penetrate the atmosphere and strike the surface at cosmic velocity.
The author(s) of this abstract have provided an email address for comments about the abstract: harrisaw@colorado.edu
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Bulletin of the American Astronomical Society, 34, #4
© 2002. The American Astronomical Soceity.