Sources:
Bach, Eleanor. Astrology from A to Z: An Illustrated Source Book.New York: Philosophical
Library, 1990.
DeVore, Nicholas. Encyclopedia of Astrology.New York: Philosophical Library, 1947.
COMETS
A comet (from the Greek word kometes,meaning “longhaired”) is a celestial body
composed of ice, rock, and frozen gases that has been quaintly described as a dirty
snowball. Almost all comets observed from Earth are part of our solar system, follow-
ing long elliptical orbits that bring them from outside the orbit of Pluto, close to the
Sun, and then back beyond Pluto. Many become involved with gravitational forces in
the planetary system, so that they subsequently follow paths that keep them consider-
ably inside Pluto’s orbit—some even become trapped inside Jupiter’s orbit. The so-
called tail of a comet is produced when the comet passes close enough to the Sun for
sunlight to heat it up, causing gas and dust particles to escape from the nucleus and
form a glowing tail.
THEASTROLOGYBOOK [165]
CometsA detail of the title page from a publication dealing with a comet from 1618. Reproduced by
permission of Fortean Picture Library.