Crater counting

Imagine you are playing a game and you have to count how many times you jump on a trampoline. Similarly, scientists in space do a similar thing when they count the number of "dents" on the surface of the moon and other planets. These holes or dents are called craters.

Scientists want to know how old different planets and moons are, and crater counting is one way to find out. Just like how old people have more wrinkles on their faces than young people, older planets have more craters than younger planets.

When a rock from outer space crashes into the surface of a planet or moon, it creates a hole, which we call a crater. The bigger the rock, the bigger the hole. Over time, more rocks hit the surface and make more holes, so planets that have been around for a long time have more craters.

Scientists use pictures taken from space to count the number of craters on the surface of a planet or moon. They then use a special formula to estimate how old the surface is based on the number of craters. This helps us understand how old the planet is and how it has changed over time.