The event took place at the end of what Earth scientists, or geologists, call the Permian Period.

这一事件发生在地球科学家或地质学家所说的二叠纪末期。

He is an Earth scientist at the University of London, who was not part of the study.

他是伦敦大学的一名地球科学家，他没有参与这项研究。

Kathleen Springer is an Earth scientist researcher at the United States Geological Survey and helped write the new paper.

凯瑟琳·斯普林格是美国地质调查局的一名地球科学家研究员，她帮助撰写了这篇新论文。

Earth scientist Jay Melosh at Purdue University said he found the number of craters too small to prove any major point.

普渡大学的地球科学家杰伊·梅洛什说，他发现陨石坑的数量太少，不足以证明任何重要观点。

After the instruments are put into orbit around Earth, scientists will compare information from the last year to learn how the Earth is changing.

在把仪器放到地球轨道后，科学家将对比去年的数据，以分析地球的变化。

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。

And this cooperation between the intelligence community and civilian scientists has evolved into the Global Fiducials Program, where the CIA uses classified technology to provide important data for Earth scientists today.

情报部门和民间科学家之间的这种合作已经演变成全球信托计划，中情局在该计划中使用机密技术为当今的地球科学家提供重要数据。

The two main chemicals that eat away at ozone are in lower levels in the atmosphere, said Newman, who is also the chief Earth scientist at NASA's Goddard Space Flight Center.

纽曼也是美国航空航天局戈达德太空飞行中心的首席地球科学家，他说，侵蚀臭氧层的两种主要化学物质在大气中的含量较低。

Back on Earth, scientists painstakingly counted 1,676 individual grains of regolith in Neil's shovelful, and in that they found 84 specks of white stuff that they didn't expect to find there.

回到地球，科学家们煞费苦心地在尼尔的铲子里数出了 1676 个单独的风化层颗粒，他们在其中发现了 84 个他们没想到会在那里发现的白色斑点。