Across
- 3. Instruments that detect and record vibrations from earthquakes, used to study Earth's interior
- 4. A Mars-sized body thought to have collided with Earth, forming the Moon
- 6. A form of an element with the same number of protons but a different number of neutrons
- 9. The gradual growth of objects in space as particles stick together due to gravity and collide, forming larger bodies like planets
- 11. The thick, semi-solid layer between Earth's core and crust, made of lighter rocks than the core and heavier rocks than the crust, such as basalts, that are mixed with gas and water
- 12. The thin, outermost solid layer of planet Earth, formed of the lightest rocks, mainly granite
Down
- 1. The process by which unstable atoms release energy and particles over time
- 2. The process by which a planet's layers separate based on density
- 5. Planets that orbit stars outside our solar system
- 7. The longest unit of geologic time, made up of multiple eras
- 8. In astronomy, this refers to all elements heavier than helium, important for forming planets and stars
- 10. The central, densest layer of planet Earth, made mainly of iron and nickel and responsible for generating the planet's magnetic field