Asteroid impact
小行星撞擊

From time to time Asteroids cross paths with us and, while impacts on the scale of the infamous 6.2-mile (10km) 'dinosaur-destroyer' are rare, an asteroid a fifth the size could spell disaster for civilisation.
雖然小行星時不時就會與地球相交，但是“令恐龍滅絕”的聲名狼藉的小行星直徑有1萬米，這種小行星非常罕見，一顆體積僅為其1/5的小行星就能給人類文明帶來一場浩劫。

With energy greater than 10 million Hiroshima bombs, the impact shock would flatten everything within a 186-mile (300km) radius.
小行星撞擊的能量比1000萬枚投放在廣島的原子彈還要強，帶來的沖擊將把方圓300公里夷為平地。

However, the CESR rate this as a low risk priority.
然而，CESR認(rèn)為這種情況的可能性較低。