Space, or outer space, is a word we use to think about everything which lives beyond the Earth.
Most of space is indeed empty space! It acts like a vacuum, with almost nothing in the space between stars and planets.
These planets and stars are packed together inside galaxies. Most stars have a system around them containing moons, asteroids, and comets. Galaxies come in different shapes and sizes, and some have cosmic dust, which feeds new stars to form.
Everything we know about space comes from studying the light that reaches us from these objects. Recently, we've also found out about things in space by looking at changes in gravity—through gravitational waves.
The study of space includes looking at all scales, from the atoms inside stars to how the Universe began and where it might end.
Explore this section to learn more about all the things we find in space.