Across 2. The hottest planet in our solar system 4. First to observe the moons of Jupiter 5. The Russian space agency 7. Any object that orbits another celestial body 8. The largest planet in our solar system 10. A natural satellite of a planet
11. A collection of billions of stars and their solar systems
12. A ball of gas, ice, rock and dust, with a stretched orbit
Down 1. An ice giant planet
3. The collection of a star and all the objects that orbit it
6. A rocky body larger than 1m, smaller than a planet, orbiting the planet
9. A large body orbiting a star, which has cleared its orbit and formed a sphere
