Across
- 5. Relating to the Sun.
- 8. Earth's twin in size and proximity.
- 9. Planet known for its rings.
- 11. Distance light travels in one year.
- 12. Icy body with a glowing tail.
- 13. The Red Planet.
- 15. All existing matter and space as a whole.
- 20. Artificial object orbiting a planet.
- 21. Path of a celestial object around another.
- 23. Planet outside our solar system.
- 27. Galaxy containing our solar system.
- 28. The universe as an ordered whole.
- 29. Once a planet, now a dwarf planet.
Down
- 1. Force that attracts objects toward one another.
- 2. Space traveler.
- 3. Theory about the universe's origin.
- 4. Largest planet in the Solar System.
- 6. Region of space with immense gravity.
- 7. Private space exploration company.
- 10. U.S. space exploration agency.
- 14. Natural light display in polar regions.
- 16. Protective clothing for astronauts.
- 17. Vehicle used for space travel.
- 18. A rocky body orbiting the Sun.
- 19. A massive system of stars and planets.
- 22. Cloud of gas and dust in space.
- 24. Relating to the Moon.
- 25. Instrument to view distant celestial objects.
- 26. A shooting star.
- 27. Earth's natural satellite.