Across
- 4. a long, steep slope or cliff on a planetary surface, often formed by tectonic forces like faulting when a planet's crust shrinks or is pushed together.
- 6. a system for detecting the presence, direction, distance, and speed of aircraft, ships, and other objects, by sending out pulses of high-frequency electromagnetic waves that are reflected off the object back to the source.
- 7. the four large, outer planets of our solar system.
- 9. the smaller, outer moon of Mars, named after the Greek god of dread, son of Ares (Mars).
- 12. the four largest moons of Jupiter.
- 13. when the external tidal forces on an object become greater than the internal forces that hold it together.
- 15. the largest impact basin on Mercury.
- 16. a large, continent-sized highland region or "terra" located in the northern hemisphere of Venus.
- 17. the larger, innermost, and irregularly shaped moon of Mars.
- 18. a disk-like structure of countless small particles (dust, ice, rock) orbiting a celestial body.
Down
- 1. a system of canyons located just south of the Martian equator.
- 2. a rocky, Earth-like planet with a solid surface, primarily composed of silicate rocks and metals.
- 3. the largest moon of Saturn.
- 5. the process where a molecule breaks apart into smaller atoms or fragments after absorbing a photon of light.
- 8. the largest moon of Jupiter.
- 10. a colossal shield volcano on Mars and the largest volcano and tallest mountain in the entire solar system.
- 11. when relatively narrow bands of strong wind in the upper levels of the atmosphere.
- 14. the largest moon of Neptune.