Across
- 3. a long, narrow groove that forms where water, lava, or other liquid flows
- 4. a mixture of gases surrounding a planet
- 5. the solid part of a rocky planet
- 10. an object, diagram, or computer program that helps to understand something by making it simpler or easier
- 11. all the living things on a planet
- 12. all the liquid and solid water on a planet
Down
- 1. a feature that forms on the surface of a planet such as a mountain, channel, or sand dune
- 2. having the conditions necessary to support life
- 6. Any planet with a solid surface
- 7. information about the natural world that is used to support or refute a claim
- 8. a proposed answer to a question about the natural world
- 9. to notice how two or more things are alike or different