Over the last 20 years, advances in the field of exoplanet discovery have excited the imaginations of scientists and enthusiasts alike. But we're in position to know yet whether a planet is habitable.
A look at some of the more obscure methods astronomers use to detect planets around other stars, in the second of a two-part series on finding world's elsewhere in the universe.
Astronomers have discovered more than 3,000 planets around other stars, so far. In the first of a two-part series we look at how they find world's elsewhere in the universe.