The Planets

Melvyn Bragg and guests discuss our knowledge of the planets in both our and other solar systems. Tucked away in the outer Western Spiral arm of the Milky Way is a middle aged star, with nine, or possibly ten orbiting planets of hugely varying sizes. Roughly ninety-two million miles and third in line from that central star is our own planet Earth, in thrall to our Sun, just one of the several thousand million stars that make up the Galaxy.Ever since Galileo and Copernicus gave us a scientific model of our own solar system, we have assumed that somewhere amongst the myriad stars there must be other orbiting planets, but it took until 1995 to find one. ‘51 Pegasus A’ was discovered in the Pegasus constellation and was far bigger and far closer to its sun than any of our existing theories could have predicted. Since then 121 new planets have been found. And now it is thought there may be more planets in the skies than there are stars.What causes a planet to form? How do you track one down? And how likely is there to be another one out there with properties like the Earth’s?

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Guests

• Paul Murdin 5 episodes
  Senior Fellow at the Institute of Astronomy in Cambridge
• Hugh Jones No other episodes
  Reader in Astrophysics at Liverpool John Moores University
• Carolin Crawford 20 episodes
  Royal Society Research Fellow at the Institute of Astronomy in Cambridge

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Programme ID: p004y25b

Episode page: bbc.co.uk/programmes/p004y25b

Auto-category: 520 (Astronomy & allied sciences)

Hello (First sentence from this episode)

Hello, tucked away in the outer western spiral arm of the Milky Way is a middle-aged star with nine or possibly ten orbiting planets of hugely varying sizes.