Across
- 5. Mars has extinct volcanoes, including a 25km tall one, and a very thin ________.
- 7. Mercury is a rocky planet with no atmosphere, no water, and no _____.
- 8. This rocky planet has 21% oxygen and 78% nitrogen in it's atmosphere.
- 9. Neptune's gas is the _______ of all the gas planets. It also has the highest wind speeds.
Down
- 1. Venus is a rocky, volcanic planet which has dense clouds of this toxic compound.
- 2. Jupiter is 90% hydrogen, has high winds, and 79 moons including _______.
- 3. Jovian planets are also called this.
- 4. Uranus has high winds, methane and this other gas.
- 6. This planet has a lot of debris, including ice and rock.