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12 votes

How do we know that a comet passed by earth 50,000 years ago?

If I say "Orbital mechanics is easy" some people who know a lot about this will get very angry. But for the purposes of this question: orbital mechanics are easy. we know where the comet is ...
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1 vote

How is Halley's comet still in one piece?

Comets are extremely volatile because mostly they consist of ice and dust, once they reach the perihelion i.e closest point to the Sun in an orbit around the Sun they sublimate forming the Coma and ...
  • 683
31 votes

How is Halley's comet still in one piece?

The basic answer to your question though is that Halley's comet is unlikely to be very old (in the sense that it has not spent a large amount of time orbiting the Sun as closely as it does now). Most ...
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8 votes

How is Halley's comet still in one piece?

Comets can be fairly large initially, multiple kilometers across. However, just as parrots become ex-parrots, comets eventually become ex-comets. They shed volatiles, sometimes shed pieces, and yet ...
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46 votes
Accepted

How do we know that a comet passed by earth 50,000 years ago?

50000 years is the comet's estimated orbital period. That does not necessarily mean that the comet was naked-eye visible from Earth 50000 years ago. That also does not necessarily mean that the comet ...
  • 31.4k

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