Apart from the Sun, its planets and their moons, our Solar System has vast amounts of space rocks – fragments left over from the formation of the inner planets.

A large concentration of asteroids forms a vast ring around our Sun, orbiting it between Mars and Jupiter. Fittingly, it’s called the main asteroid belt. Comets are icy bodies of dust and rocks that originated even farther away – in the Kuiper Belt beyond Neptune and the Oort Cloud of debris surrounding the Solar System.

Extraterrestrial rocks come in many sizes. Generally speaking, asteroids are space rocks larger than one metre, while the smaller pieces (from two millimetres up to one metre in size) are known as meteoroids.

Regardless of where they come from, once these foreign rocks make it to Earth’s surface, we call them meteorites. But they are much more than just simple rocks from far, far away.

They have allowed us to estimate the age of our planet, and changed the course of evolution more than once. Here are six major ways meteorites and comets have contributed to Earth’s history or our knowledge of it.

1. The age of our planet

2. The building blocks of life

3. How we got our oceans

4. Changing the course of evolution

5. Sampling Earth’s deep mantle and core

6. Meteorite impacts gave us huge gold and nickel deposits