What started as a tool for military surveillance is now essential to earth scientists examining changes in landscapes over time.

最初作为军事监视工具的东西现在对于地球科学家检查景观随时间的变化至关重要。

At an altitude of 50 to 130 kilometers or 31 to 81 miles above the earth, scientists believe that sprites have been responsible for many mistaken UFO sightings.

在距地球五十至一百三十公里（31 至 81 英里）的高空，科学家们认为，许多误认为是不明飞行物目击事件都是由“精灵”造成的。