Across
- 4. Earth's ____around the sun is not a perfect circle.
- 7. Many plants and animals live on our planet's ____.
- 8. Without _____, people on Earth would float into the air.
- 9. Stars and planets are not empty, but are full of ____.
- 11. The _____ studied the moons of Jupiter.
Down
- 1. Earth is _____ in our Solar System because it has people.
- 2. probe, Scientist sent a _____ to Mars to collect informatio.
- 3. There is a big ____ between the Sun and Earth.
- 5. The ____ of the planet Mercury is only 4,879 kilometers.
- 6. You can see the moon's _____ with a telescope.
- 10. The _____ of Earth is 1,800 miles below the surface.