Earth science is an important field of study for unraveling the mysteries of nature.

I am an Earthling.

We are searching for extraterrestrial life.

The process of terraforming is part of transforming other planets into a habitable environment for humans.

He learned the old character form of 學 to study ancient documents.

This is a historic building.

He recognizes the importance of oral history.

He interprets world events from a historicism perspective.

He is a famous historian and has written many history books.

He is trying to hide his embarrassing past.