Unit 5

4. Planets: Celestial bodies that orbit the Sun, are massive enough to be rounded by their own gravity, but have not cleared their orbital neighborhood of other debris.
6. hypothesis: The leading theory of solar system formation, suggesting the Sun and planets formed from a spinning disk of gas and dust.
8. dust: Small particles of dust found throughout the solar system.
9. Small rocky or metallic bodies that orbit the Sun.
10. The curved path an object takes around a star or moon, held in place by gravity.
11. The fundamental force that holds the solar system together, causing objects to orbit the Sun and driving the formation of planets from smaller bodies.
12. Large celestial bodies that orbit the Sun, including the inner planets (Mercury, Venus, Earth, Mars) and outer planets (Jupiter, Saturn, Uranus, Neptune).
13. The star at the center of our solar system.

1. Larger bodies that grow from planetesimals and continue to accumulate mass, eventually becoming planets or dwarf planets.
2. Small, planet-like bodies that formed from the accretion of dust and gas.
3. The process where dust and gas in the nebular disk clump together, growing from microscopic grains to larger planetesimals through collisions.
5. Icy, rocky bodies that develop a tail as they get closer to the Sun.
7. Rocky, airless remnants left over from the early formation of our solar system. They are mostly found in the asteroid belt between Mars and Jupiter.