Astronomers remove Pluto's 'planet' status

Leading astronomers on Thursday approved historic new guidelines under which distant Pluto is no longer defined as a planet. After a tumultuous week of clashing over the essence of the cosmos, the International Astronomical Union stripped Pluto of the planetary status it has held since its discovery in 1930. It is the first time that scientists have had a definition of what is - and is not - a planet.