地球外的

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

地球生命的理论是基于陨星上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.

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