Cosmologists answer questions about the shape and size of the cosmos, and how, by decoding radiation from the dawn of time - 15 billion years ago - they can discover the limits and the ultimate destiny of the Universe.

In recent years, astronomers have been caught up in one of the most exciting scientific quests - to find new planets around distant stars. Planets from Hell tells the story of these hostile new worlds that have been discovered and explores the tantalising possibility of one day finding a planet like Earth.

A look at how our solar system is teeming with thousands of asteroids and comets. While an impact would be catastrophic for human life, it is now thought these mini-worlds played a vital part in kick-starting life on our planet. Following NASA's successful landing of a probe on an asteroid, these mysterious objects are now yielding their secrets.