By tracking the movements of the Moon, Venus, and other heavenly bodies, the Mayans realized that there were cycles in the Cosmos.

通过跟踪月球，金星和其他天体的运动，玛雅人意识到宇宙有循环周期。

youdao

Satellites beyond Earth use radio waves for tracking and communication, but the moon satellite is the only one to rely on lasers for tracking, NASA said.

CNN: STORY HIGHLIGHTS

During that time, the GRAIL satellites will be tracking the distance between each other as the Moon passes beneath them.

FORBES: NASA's GRAIL Mission Will Unlock Secrets Of The Moon's Interior