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Do comets have a limited number of orbits?

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    $\begingroup$ Do you mean how many orbits a comet can follow around the Sun or if there is a limited number of "spins" a comet can make around it? Please clarify. $\endgroup$ – Daniel Ibaseta Nov 22 '17 at 15:59
  • $\begingroup$ @DanielIbaseta I have a question in the test that is: Related to comets: all the comets have a limited number of orbits. Probably around a planet $\endgroup$ – Tiago Gonçalves Nov 22 '17 at 16:13
  • $\begingroup$ @DanielIbaseta why is this true? The comet can go to the infinite space $\endgroup$ – Tiago Gonçalves Nov 22 '17 at 16:14
  • $\begingroup$ Your test question is not clear enough, as I am out of context I can't give you a proper answer. Maybe a photo of your test or a proper transcription would help to solve the problem. $\endgroup$ – Daniel Ibaseta Nov 22 '17 at 16:38
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    $\begingroup$ Your question is unclear: Comets do not orbit planets; they orbit the sun. There is no fixed limit on the number of times a comet can orbit the sun. Comets contain water. Eventually the water will boil away. $\endgroup$ – James K Nov 22 '17 at 17:39
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Everything in the universe has a limited number of orbits. But the way to make sense of your question is to ask how long comets last. Comets lose ice when they fly past the sun, so they get smaller each time. How much smaller depends on how close they get to the sun and their composition, or how easily they "melt" or break apart. (Ice doesn't exactly melt in space, it sublimates when it heats up)

Sungrazers have a very limited number of orbits. Halley's also is expected to have a limited lifespan of about 100 more orbits before it stops being a comet and basically becomes a rocky body. Halley's passes closer to the sun than Venus at its perihelion, so it loses a lot of ice, each pass, which helps make it's tail impressive. (when Earth and Halley's are properly aligned that is).

Your question also depends on your definition of a comet. Will Halley's still be a comet after it loses it's ice and it's tail? (sometimes called a Manx comet). That's a matter of interpretation. It will get smaller, but it will likely remain in orbit for some time after it loses it's ice.

Orbiting objects that cross planetary orbits are also, on average, less stable, but I suspect that's another subject. Halley's might be destined to crash into the Earth, or the Moon at some point. It's orbit nearly intersects the Earth's orbit in two places. But don't worry. That's not going to happen anytime soon, if it happens at all.

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    $\begingroup$ Halley's comet. $\endgroup$ – Rob Jeffries Nov 23 '17 at 1:26
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    $\begingroup$ @RobJeffries Thanks for that. I've always made dumb spelling mistakes. Math geek but close to last in my class in English and languages. $\endgroup$ – userLTK Nov 23 '17 at 5:21

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