We know the Sun to be the centre of our solar system, just as other stars form the centre of many other solar systems. The Earth and the other planets in our solar system revolve about the Sun. But our sun is on the outskirts of a galaxy called the Milky Way, and the Milky Way is not the only galaxy.
The universe is thought to contain something like 100 billion galaxies, and each galaxy might contain something like 100 billion stars. Outer space is the void beyond any celestial body, such as planets and stars. There are only a few particles scattered here and there in space, whereas a cubic metre of the air we breathe on Earth contains millions of molecules.
Scientists in this zone could be designing satellites, telescopes or launchers and analysing their data. Or they might be working to improve our understanding of the universe and what’s happening on our own planet.