ABSTRACT
Most of the planets in the Solar System are attended by satelUtes. To date the Earth is known to have one, Mars two, Jupiter sixteen, Saturn eighteen, Uranus fifteen, Neptune eight and Pluto one; this gives a total of sixty-one. Only Mercury and Venus are unaccompanied. Theoretically I suppose we might tack on Dactyl, the midget satellite of the asteroid Ida, and the as yet unnamed satellite of another asteroid, Dionysius, but for the moment let us keep to the main planets.
