Black Holes in Space
What is a Black Hole? Nobody can yet be sure; it may be the final state of a very massive star which has collapsed, surrounding itself with a ' forbidden zone' from which not even light can escape. Patrick Moore discusses these remarkable objects, which have become so important in modern astronomy, with lain Nicolson of Hatfield Polytechnic Observatory.
Producer PATRICIA WOOD
The Sky at Night 5, £4.00 from bookshops