Sue Lawley's castaway on this week's Desert Island Discs is Astronomer Royal Sir Martin Rees. As well as choosing his eight records, book and luxury, Sir Martin will be discussing his work in cosmic evolution, or, to put it more simply, how the Earth and Solar System were formed. He tells of his belief that it is more difficult to understand a frog than the cosmos.

[Taken from the original programme material for this archive edition of Desert Island Discs]

Favourite track: In Paradisum by Gabriel Fauré