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Learn about comets, the "dirty snowballs" made of ice and rock debris orbiting the Sun. Discover their orbits, tails, and different types like short-period and long-period comets. Dive into famous comets like Halley's and how comets contribute to understanding the solar system's formation.
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What is a Comet? • Comet: A chunk of frozen gases, ice, and rocky debris that orbits the Sun “dirty snowball”
Comet Orbits vs. Planet orbits Comet orbits: • long, highly elliptical • sometimes close to the sun; sometimes very far from the sun Planet orbits: • more circular • distance from sun fairly constant
Comet Tails: point AWAY from the sun • The coma forms when the sun’s energy causes the frozen gases to “sublimate.” • The solar “winds” push the coma away to form the tail.
Short-period Comets Long-period Comets Orbital periods of < 200 years from the Kuiper Belt beyond Neptune’s orbit are the ones usually seen from Earth Orbital periods > 200 years from the Oort Cloud on the outskirts of the solar system Two Main Categories of Comet:
Comets: leftover debris from the formation of the solar system 4.6 billion years ago! • Scientists want to study comets to learn more about the formation of the solar system.
A famous comet: Comet Halley • Edmund Halley predicted its return • orbital period: 76 years • Last seen from Earth 1985-1986 • When will it return….?
Comet Halley Actual photograph of the nucleus of Halley’s Comet
Comet C/ 2011 L4 PanSTARRS – named for the telescope through which it was discovered in June 2011: Panoramic Survey Telescope and Rapid Response System (or PAN-STARRS), a telescope atop the Haleakala volcano in Hawaii.
When will PanSTARRS return?Maybe never!It looks like this comet’s orbit might be parabolic… If it does return, it might not be for another 100,000 years…
Comet C/2012 S1 (ISON) Should be visible in late November – maybe even in the daytime!
Speculation: Is this the same comet as the Great Comet of 1680?????
http://amazing-space.stsci.edu/resources/explorations/comets/lesson/lab.html1. Make your own virtual comet.2. Read some comment myths and legends.3. Test your knowledge with “Comet Tails.”