Key Terms

2. a layer of a star where energy is transported outward in the form of light
6. are much like other planets but are smaller and do not always clear a path around the sun
9. a thin, colorful layer of gas in the sun's atmosphere located above the photosphere
11. helps us see distant objects such as stars, planets, and galaxies by collecting and focusing light or other types of energy like radio waves
12. is anythings that orbit things
14. is the visible surface of the sun or the layer of the sun that emits light
16. the outermost layer of the sun's atmosphere
17. are massive balls of hot gas that produce light and heat through nuclear fusion
18. the distance traveled by light in one year,
22. average distance from Earth to the sun (~150 million km)

1. are made mostly of gases (gas giants): Jupiter, Saturn, Uranus, and Neptune
3. The sun is at the center; the Earth and planets orbit around it (Copernicus supported by Galileo)
4. any object orbiting the Sun that is not classified as a planet, dwarf planet, or natural satellite
5. a planet made of rock or metal with a solid surface
7. the process by which two light atomic nuclei combine to form a single heavier one while releasing massive amounts of energy
8. is a group of objects orbiting a central star (sun) including planets, moons, asteroids, and comets
10. a region within a star where heat is transported by moving material rather than radiation
13. Earth at the center of the universe (Aristotle & Ptolemy)
15. a group of stars that form patterns in the sky
19. powerful engines that are used to send things to space
20. a stream of charged particles that flows outward from the sun's outermost atmosphere
21. is the study of space, including stars, planets, moons, galaxies, and black holes