Part 10Wednesday, February 16, 202211:37 PMComets and Asteroids: Comets:-Unlike any other object in the night time star, their apperance is erratic and unpredicatableMost Famous Commet: Halley's Comet:-Issiac newton noted that the comet appeared in 1680 following a parabolic orbit, and caclulated its orbit using mathmatical equations-Soon Edmond Halley used Newton's method and looked back athe ancient recordings and foundthat over time this single comet wheeled around the sun and is in a closed ellipse every 75 yearsor so.-He predicted the next visit in 1758-9, and the comet thereafter bore his name Question: Based on the information that you read, which year did Halley's Comet return last?Answer: 1986!Comets generally trend:-Most are periodic and orbit around the sun that in a time period that is fized-If we know the period we can predict when a comet is going to appear exactly, as we saw in the case of Halley's cometPeriods of Comets differ Significantly:-Halepopp has a period of 2400 years-Hyakutake 14000 years-Enckle 3.3 yearsBased on time periods astronomers classify comets into two categories-Short period comets: period of less than 200 years-Long period comets: periods of greater than 200 years and have orbits that are often unpredictable. (difficult to detect and catalouge, they may not always return on their steps)Question: Identify, which of these are classified as short period comets and which ones are long period comets.Answer: !D: Comets Ikeya-Seki and Hale-Bopp are long period and the other two are short period.!!!!!Why do comments have varied periods:-Small bodies orbiting the sun beyond neptune and they are called trans-neptunians with diameters larger than 100 km outward of orbit ofNeptune 30-50AU-They are confined within a thick band around the elliptical leading to the realization that they occupy a ring or belt surrounding the sun. -Referred to as the Kuiper Belt, after the Dutch-American astronomer Gerald Kuiper. -Some of the kupier belt objects get thrown out of their stable otbit from the gravitational perturbation from giant planets like Uranus and Neptune. -Due to the the gravitational force from the
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