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The
Spaceguard Survey - Protecting the earth from
cosmic impacts |
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MORRISON, DAVID |
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AA(NASA,
Ames Research Center, Moffett Field, CA) |
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Mercury
(ISSN 0047-6773), vol. 21, no. 3, May-June
1992, p. 103-106, 110. |
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06/1992 |
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Lunar
and Planetary Exploration |
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STI |
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EARTH
SURFACE, HYPERVELOCITY IMPACT, METEORITIC
DAMAGE, METEOROID HAZARDS, ASTEROIDS, COMETS,
METEORITE CRATERS |
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1992Mercu..21..103M |
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The conclusions of the NASA International Near-Earth-Object
Detection Workshop (May 1991-January 1992) are summarized.
Near-earth asteroids and short-period comets constitute about
90 percent of potential earth-impacting projectiles. The greatest
risk is from those with diameters greater than 1 km. The objective
of a near-earth object survey is to find such objects, calculate
their long-term orbital trajectories, and identify any that
may impact the earth over the next several centuries. There
will generally be a period of at least several decades to
take corrective action if any potential earth-impactors are
found. A region of space extending outward from the earth
to approximately the inner edge of the main asteroid belt
must be monitored. Detection can be by reflected sunlight
or infrared. Though faint, the objects should be readily detectable
with ground-based telescopes, and thus there is no need for
a more expensive space-based system.
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