translation.en: A small asteroid, say a half mile wide, would touch off firestorms followed by severe global cooling from the debris kicked up -- Carl Sagan's nuclear winter thing.
translation.zh: 一颗大概直径半英里的小行星，可能会引起风暴性大火 紧跟着残骸产生的极度严寒遍及全球—— 卡尔 萨根所描述的核冬天——