Comet Halley first becomes visible on a photographic plate.

Comet Halley has also been mined for water ice in another episode.

The letter referenced Comet Halley and announced a new project to begin in the spring of 2011.

Comet Halley would be magnitude 1.0 at the same perihelion distance.

The periodic variation in the activity of Comet Halley during the 1985/1986 apparition.

April 20 - Comet Halley is visible from Earth.

May 18 - The earth passes through the tail of Comet Halley.

By contrast, Comet Halley has passed the sun more than 100 times, coming close enough to have been greatly altered from its original condition.

Amongst his other observations during this time was that of the return of Comet Halley.

November 16 - Comet Halley reaches perihelion, its closest approach to the sun.