The Sky At Night: 22x5

The Asteroids

The asteroids or minor planets are among the most interesting of the junior members in the Solar System. Only one – Vesta – is ever visible without a telescope, but thousands are now known to exist; some swing near the Earth, and several close approaches have been recorded. In this programme Patrick Moore discusses the origin and nature of the asteroids, and Gordon Taylor, of the Royal Greenwich Observatory, describes his ingenious method of measuring their sizes.