One theory about the existence of extraterrestrial life rests on the presence of carbon compounds in meteorites.

地球外存在生命的理论陨星上存在碳化合物质这一事实的。

The temperature at Earth's exobase oscillates but is typically about 1,000 kelvins, implying that hydrogen atoms have an average speed of five kilometers per second.

地球外气层底的温度不断变动的，不通常约1000K，使得氢原子平均的速度为每秒5公里。