殞石撞地球

Russian scientist spies mountain-sized asteroid heading our way-蘇俄科學家窺見如一座山大小的行星衝向地球

A Russian astrophysicist says his team has located a huge, mountain-sized asteroid whose orbit crosses the Earth's every three years. 它的軌道每三年橫過地球一次

Even though experts say the giant object, known as 2014 UR116, poses no immediate threat of collision, its unexpected discovery underscores how little is still known about asteroids and their unpredictable orbits. 雖未對地球造成立即危險，但其意外發現勾畫出對小行星及其軌道瞭解太少

Vladimir Lipunov, a professor at Moscow State University, announced the find in a short documentary, "Asteroid Attack," posted on the website of the Russian Space Agency on Sunday. Mr. Lipunov says the asteroid, which he calculates is 370 meters in diameter, could hit the Earth with an explosion 1,000 times greater than the surprise 2013 impact of a bus-sized meteor in Russia. That object entered Earth’s atmosphere over the city of Chelyabinsk, resulting in a series of ferocious blasts that blew out windows and damaged buildings for miles around. 此小行星據估直徑370米，如撞擊地球會產生1000倍於2013年像公車那麼大殞石的力量。

12/08/14