a moon that orbits a planet a planet that orbits the Sun a very large system of stars that is held together by gravity a very large system of planets that is held together by the Sun
What is a galaxy?

Options:
- a moon that orbits a planet
- a planet that orbits the Sun
- a very large system of stars that is held together by gravity
- a very large system of planets that is held together by the Sun

a very large system of stars that is held together by gravity