It is 40 years since Sir David Attenborough told the story of Life on Earth, from its very first spark 4 billion years ago to the abundance of plants and animals today. He tells Andrew Marr how more pieces of the puzzle have fallen into place over the last four decades.

The German ornithologist Michael Quetting spent a year hand rearing seven goslings: caring for them as they hatched, helping them learn to swim, and teaching them to fly alongside his aircraft. The project is part of an ambitious scientific research programme to understand birds in flight and use them to gather weather data for us.

Lord Martin Rees, the Astronomer Royal, looks beyond the earth to ask about potential life among the stars. He sees the future of humanity as bound to the future of science, and believes that space explorers in the next century will be electronic and not organic.

A hundred years after Holst wrote The Planets, leading composers are again trying to capture the essence of our solar system in music. But this time they are working in collaboration with scientists. The geologist Dr Philippa Mason has helped bring deeper insight to Venus: a planet once thought to be a lush tropical swamp world, but in reality a crushing, violent inferno.

(Producer: Katy Hickman).