British astronomers have made the first "sighting" of a planet orbiting a distant sun. The discovery, a landmark in astronomy, makes the detailed study of extra-solar planets a practical possibility. By analysing the light they reflect from their parent stars, astronomers will be able to work out their composition and their composition and their composition and their atmospheres. Ultimately, this could lead to the discovery of planets that could harbour life. But the new planet, a gas giant like Jupiter, is certainly uninhabitable. The 'new world' nicknamed. The Millannium Planet, orbits a star called Tau Bootis, which is 55 light years from Earth.