1. Which planet is closest to the Sun?

2. What force keeps planets in orbit around the Sun?

3. Which scientist proposed the laws of motion?

4. What is the point of no return around a black hole called?

5. Which famous experiment demonstrated that electrons behave as both waves and particles?

6. What is the primary element that stars fuse in their cores during the majority of their lives?

7. What powers the incredible energy output of a quasar?

8. The Equivalence Principle states that gravity is indistinguishable from what other phenomenon?

9. What happens to a moon that crosses the Roche Limit of its parent planet?

10. What essentially 'froze' the sound waves of the early universe into the BAO we see today?

11. Which Lagrange Point is home to the James Webb Space Telescope?

12. According to the rocket equation, what makes up the vast majority of a rocket's mass at launch?

13. What is it called when a galaxy's light shifts toward longer wavelengths as it moves away from us?

14. What is the name of the galactic supercluster that contains the Milky Way?

15. What three phases coexist at the triple point?

16. Which organisms were primarily responsible for the Great Oxidation Event?

17. Which diagram plots a star's luminosity against its temperature?

18. What did Einstein call the phenomenon of quantum entanglement?

19. The hypothesis of Planet Nine is primarily based on what type of scientific evidence?

20. If Planet Nine exists, its orbital period around the Sun is estimated to be approximately how long?