29/30 Astronomers in the past decade have tried to find other planets like Earth in the universe
28/30 How the use of infrared telescopes increased our understanding of distant planets.
27/30 Heather Couper looks at research that shows stars are like controlled nuclear explosions.
26/30 Heather Couper looks at William Herschel's discovery of infrared radiation 200 years ago.
25/30 Heather Couper looks at arguments over the laws of physics and the universe's creation.
24/30 What we can see is only a fraction of matter in the cosmos. Heather looks at dark matter.
23/30 Heather Couper looks at the discovery of quasars, huge black holes a long way from Earth.
22/30 Heather Couper considers how the concept of black holes gained credence in astronomy.
21/30 The discovery of radio waves in space, and how it led to the discovery of the pulsar.
20/30 The Big Bang theory of how the universe began, and what its opponents think.