Scientists said they have found evidence of a giant planet far out in our solar system.In astatement, the California Institute of Technology—Caltech—said this planet travels a verystrange “longandthin orbit in the distant solar system.”The discovery was made by tworesearchers at Caltech: Konstantin Batygin and Mike Brown. They used mathematicalmodeling and computer simulations (模拟) to find the planet.So far, there have not been anydirect observations of the planet.“My jaw hit the floor, ” said astronomer (宇航员) Mike Brown, the moment he realizedthere might be a ninth planet. 

The scientists said it would take this planet 10,000 to 20,000 years just to make one fullorbit around the sun. The new planet, called “Planet Nine ” , has a mass about 10 times the sizeof Earth.If they are right, the newly found planet would be the ninth planet in our solar system.Pluto (冥王星) had been called the ninth planet until 2006, when it was renamed a “dwarfplanet.”