Saturn

Observing Saturn

Saturn is the furthest planet easily visible to the naked eye and must have been known since prehistoric times. It is much fainter than Jupiter and Venus but normally outshines Mars and often Mercury. Saturn is at its brightest when the rings are face-on to the Earth.

A drawing of Saturn as seen through the Royal Observatory's 28-inch refractor.
Image: Sally Russell

With a pair of binoculars Saturn looks like a small non-circular dot. A small telescope shows the ring system and the largest satellite, Titan. The axial tilt of Saturn means that the rings change their tilt with respect to the Earth as the planet moves around its 30-year orbit. Every 15 years the rings appear edge-on to the Earth and almost disappear.

Larger telescopes reveal the broad A and B rings, separated by the Cassini division, and the innermost faint C or Crepe ring. Together with Titan it is possible to see around half a dozen fainter satellites.