ELI5: Explain Like I'm 5

Lunar geologic timescale

The lunar geologic timescale is like a big calendar but instead of being measured in days and months, it's measured in millions of years. It's used to help us figure out how old different parts of the moon are. It also helps scientists better understand how the moon has changed over time. It's like a timeline that covers 4.5 billion years. We can learn about the moon's history by looking at these different time periods!