Beyond Pluto: Exploring the outer limits of the Solar System by John Davies,
Cambridge University Press, £17.95, ISBN 0521800196
OUT THERE in the cold, dark outer disc of our planetary system a jumble of
objects is slowly orbiting the Sun. They’re too small to be planets, but they
aren’t moons either. They are called plutinos, after Pluto, the biggest of them
all. Pluto was discovered in 1930 and orbits the Sun twice for every three
orbits of Neptune.
A bunch of astronomers predicted that Pluto was not alone—Kenneth
Edgeworth in 1943, Gerard Kuiper in 1951 and Fred Whipple in…
