An object of a superior size in the middle of that of Pluto has just been discovered in the Kuiper belt. This one consists of objects made by ice and by rock in orbit around the Sun and situated beyond Neptune. The discovery, realized by Michael Brown and Chadwick Trujillo, of Caltech (Pasadena, the United States), tends to confirm the hypothesis according to which the Kuiper belt shelters objects of dimension comparable to that of Pluto. It strengthens the position of the astronomers classifying Pluto not among planets but among objects of the Kuiper belt, the biggest of them for the moment. The new object, called Quaoar, whose diameter is 1250 kilometers, is the biggest object of the Solar system updated since Pluto, discovered in 1930. It follows a circular trajectory in approximately 6.3 billion kilometers of the Sun and 1.8 billion kilometers of Neptune. | Pluto follows an elliptic trajectory bringing it inside the orbit of Neptune and beyond that of Quaoar. Consisted for half of the ice and for half of the rock, Quaoar " is black, of the dirty ice ", clarifies Brown. it was made black by the ultraviolet light which transformed little by little its organic compounds, and it since the debuts of the Solar system, the objects of the Kuiper belt being the rests of the period of the formation of planets. |