Tenth Planet Larger Than Pluto

When UB313 was discovered a little more than a year ago, it was immediately believed to be larger than Pluto based on its greater brightness. However, UB313 orbits the Sun in a highly elongated orbit, bringing it twice as far away from the Sun as Pluto, making it difficult to measure its diameter directly. Finally, German astronomers using the 30m IRAM Telescope in Spain have arrived at an estimate for UB313's diameter at around 3000km, roughly 700km larger than Pluto. Based on its large distance from the Sun, UB313's surface temperature is believed to be around -250 degrees celsius, and because of their similar albedos, it is believed to have a surface similar to that of Pluto: frozen methane and nitrogen snow. With this measurement of UB313's diameter, it is the largest body found in the Solar System since the discovery of Neptune in 1846.