Nice book for children and teens about the imminent approach of Halley's comet. Excellent quotation by Seneca. This books shows how important Halley's comet was to the development of astronomy due to its brightness and its reasonably frequent appearances. It may have been 100 times as bright when Julius Caesar saw it. Discusses theories of cometary motion. Halley's prediction could not be expected to be all that close, because at that time the outer planets, which would have effected the comets motion were unknown. Even now, comets are a bit unpredictable, because they may eject matter as they approach the sun. Comet Kohoutek was a _long_ period comet.

This book discusses planned or intended expeditions to the comet by the US, European, Japanese and Soviet space programs. I wonder how many of them came off?

Comet orbits can have any relation to the plane of the solar system.

Lots of black and white illustrations, some diagrams, some photographs, some artist's rendering.

A deal of speculation. Perhaps Halley's comet was originally a long period comet that passed very close to Jupiter and was thus deflected into a different, much smaller orbit. No reason advanced as to why that might be the case. ( )