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Abstract


Comet Vulcan\'s Unobserved August 17, 1999 Flyby

Glen W. Deen
Year: 2010 Pages: 10
This paper presents a case for a comet\'s low-altitude flyby of Earth on August 17, 1999 with a perigee over Nairobi, Kenya that nobody observed. This flyby maneuver is inferred from two daylight observations near the Moon on August 11, 1999 (during a solar eclipse) and August 14, 1999 (my own observation of a lunar transit 10 minutes before sunset), and one nighttime observation in the glare of a bright star on April 6, 2000 by an astronomer attempting to observe an asteroid occultation of that star. This paper offers a possible, if im-probable, explanation as to how this comet could have managed to avoid being seen at night under such circumstances over that time span. This paper suggests five strategies for a comet to escape observation by comet hunters. This comet has apparently used each strategy at one time or another to escape detection.

The geocentric 2-body orbits in this paper are preliminary because they ignore the gravity of the Moon, the Sun, and the other planets. Consequently I do not use any observations before August 17, 1999 in deter-mining the orbital elements. Instead, I assume that this comet flyby event triggered the 7.6 magnitude Izmit, Turkey earthquake that occurred on August 17, 1999. My plan is to cure this deficiency (2-body orbit) in a sub-sequent paper that will use the Jet Propulsion Laboratory\'s Horizon Ephemeris System to perform a rigorous numerical integration of the equations of motion. The initial heliocentric state vector for that integration will be computed from the state vector at the perigee of one of the preliminary orbits specified in this paper.