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Name: Ronald S Reil
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I have a student who asked how long the tail of Halley's Comet was at the time of its closest approach to the Sun during its 1985-1986 visit. I have searched without success for the answer. Any help would be greatly appreci- ated.

Sorry, I do not know the answer specifically for Halley's 1985 apparition, but in general comet tails can be as long as 1 AU. (an Astronomical Unit, AU, is the distance from the Earth to the Sun, 92 million miles)


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