Across
- 2. — Jupiter and Saturn have strong gravity because they have a large amount of __________.
- 4. — __________ is a force of attraction between all objects in the universe.
- 7. — Rockets, infrared light, and telescopes are examples of __________ used to learn about the solar system.
- 8. __________ and Saturn are the planets that have the most moons.
- 9. — The invention of the __________ in the 1600s dramatically increased our understanding of the solar system.
Down
- 1. Gravity pulled ______ and gas together to form the planets.
- 2. - ___________and technology helped scientists learn about the solar system by providing new ways to collect information and make more accurate calculations.
- 3. — __________ played an important role in scientists’ understanding and exploration of space.
- 5. — Placing the Hubble Space Telescope in space allows it to take clearer pictures without interference from Earth’s __________.
- 6. — Gravity keeps the planets in orbit around the __________.