Eyes wide shut
Article Abstract:
New research indicates that the number of threatening near-Earth objects (NEOs) larger than 1 km in diameter is only half the previous estimates. It is reported that there are almost 1,000 NEOs larger than 1 km in diameter and that, at the current rate of discovery, it will take 20 years for 90% of these objects to be found. Concentrating on NEOs larger than 1 km overlooks the threat from smaller but much more numerous objects. The Earth's atmosphere gives only limited protection against objects larger than 100 mt in diameter, which are much more likely to strike.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2000
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Chemical processing in the coma as the source of cometary HNC
Article Abstract:
Hydrogen isocyanide (HNC) molecules discovered in comet Hyakutake may be surviving interstellar material. HNC may also be produced by photochemical processes in the coma. It is shown that the HNC/hydrogen cyanide (HCN) ratio for the Hale-Bopp comet varies with heliocentric distance similar to predicted models of gas-phase chemical production of HNC in the coma. It is concluded that HNC is formed mainly by chemical reactions in the coma.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1998
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The size and albedo of the Kuiper-belt object (20000) Varuna
Article Abstract:
Research is presented describing the determination of the size and albedo of Varuna, an object observed in the Kuiper belt area of orbit around the sun, beyond Neptune. The size and albedo are determined using simultaneous measurement of reflected optical light and thermal emission of Varuna.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2001
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