Unit 1: The Solar System

1. ______________ was the first large planet to develop in the outer solar system.
2. _______________ elements, such as ices and gases like hydrogen, comprise the planets further from the Sun, where it is cool.
4. The planetesimals in the area between Jupiter and Mars are known as the _____________ belt
7. Terrestrial planets have _____________ atmospheres compared to Jovian planets.
9. Planets vary greatly in size, from the tiny ____________ to the massive Jupiter.
10. In our solar system, dwarf planets are found in the Kuiper Belt and asteroid belt.
12. ___________________are the solid bodies, reaching hundreds of kilometers in diameter, that formed as smaller particles collided and stuck together.
13. Stars and planets are formed from clouds of gas and dust, called interstellar clouds or a _________________.
16. Jovian planets have thick atmospheres primarily composed of ____________ and helium.
17. Classifying planets helps us to understand planetary _____________________.

1. The ______________ planets are the outer planets of Jupiter, Saturn, Uranus, and Neptune.
3. The ________________ planets are the inner four planets of Mercury, Venus, Earth, and Mars.
5. ___________ planets are smaller celestial bodies that orbit the Sun, but have not cleared their orbital paths.
6. Our solar system may have begun when interstellar gas started to ______________ as a result of gravity and became concentrated enough to form the Sun and planets.
8. Earth is one of nine planets revolving around, or ________________, the Sun.
11. ___________________ use Earth-based observations and data from probes to derive theories about how our solar system was formed.
14. The ____________ of our solar system have various sizes, surface conditions, and internal structures.
15. ________________ elements, such as iron, comprise the terrestrial planets, which are close to the Sun.