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When was Halley's Comet last visible?

When was Halley's Comet last visible?
9 February 1986
Its 1986 perihelion, the worst viewing in two thousand years

The 1986 return was the least favourable in around two millennia — the comet and the Earth were on opposite sides of the Sun at the point of maximum brightness, so it was faint and low. Its orbital period is about 75 years, so the next perihelion is expected in 2061, and the geometry then is much better. Anyone who saw it in 1986 and sees it again will be one of a very small number of people to have seen it twice.

What
Its 1986 perihelion, the worst viewing in two thousand years
When
9 February 1986
Category
Space
Could this change?
Not in any foreseeable way. The event is closed.

Space

Question When
When did the Space Shuttle last fly? 21 July 2011
When did a human last walk on the Moon? 14 December 1972

This page gives a date and never a "years ago". These pages are built as static files, so a computed interval would freeze at build time and quietly become wrong — which on a reference site is worse than making the reader do the subtraction.

Common questions

When was Halley's Comet last visible?
9 February 1986 — Its 1986 perihelion, the worst viewing in two thousand years.
What happened?
The 1986 return was the least favourable in around two millennia — the comet and the Earth were on opposite sides of the Sun at the point of maximum brightness, so it was faint and low. Its orbital period is about 75 years, so the next perihelion is expected in 2061, and the geometry then is much better. Anyone who saw it in 1986 and sees it again will be one of a very small number of people to have seen it twice.

Related pages

Sources

  1. NASA — National Aeronautics and Space Administration (Public domain (US Government))

How these figures are compiled and checked