Across
- 2. a comet's tail points __ from the sun
- 5. ____ isotopes: this is one reason for Earth's hot interior
- 10. a sphere around the solar system where comets exist
- 14. in order to be a planet, an object must clear its orbit of __
- 15. ice, rock, and metal form this small solar-system object
- 16. Jovian planets have ___ orbital periods
- 18. all Jovian planets have them around them
- 19. orbit the ___: a criterion to be a planet
- 20. this process makes the inside of Io volcanically active
Down
- 1. a.k.a. Jovian planet
- 3. main component of Jovian planets (state of matter)
- 4. terrestrial planets have ___ (3 words) moons
- 6. potato-shaped object of rock and metal
- 7. unable to clear its orbit, e.g. Pluto
- 8. one of the inactive planets
- 9. a.k.a. terrestrial planet
- 11. this is where many comets are located
- 12. where most asteroids are
- 13. process that stabilizes an atmosphere
- 17. medium and large moons are shaped like this