The solar system consists of the Sun and everything that orbits around it due to its gravitational pull. The Sun contains over 99% of the mass of the entire solar system. It was once believed that Earth was the center of the universe (geocentric model), but it is now known that the Sun is at the center (heliocentric model) and the planets orbit the Sun in elliptical orbits, as discovered by Johannes Kepler. The solar system also contains smaller objects like comets, asteroids, and meteoroids.

1. Ch. 16- The Solar System

3. 1. __________________- Earth-centered geocentric universe

7. 2. __________________- sun-centered (revised by __________) heliocentric universe Copernicus

8. 1st proposed by Greek philosopher, Aristarchus of Samos.

10. 3. ____________- the sun and all of its satellites A. The sun contains _____% of all the mass in our solar system Solar system 99.86

11. B. Johannes ______ discovered that the planets orbit the sun in ________ orbits. Kepler elliptical 1) _________- closest 2) ________- farthest perihelion aphelion

12. 4. ________- an average middle-aged star that shines with yellow light A. ____________- lowest layer of the sun’s atmosphere from which light is given off; surface- 6000 º C. B. _____________- from photosphere to about 2000 km C. ________- above transition zone for millions of kilometers into space; temps to 2,000,000 º C; seen during an aclipse the sun photosphere chromosphere corona

14. E. __________- charged particles that escape from the corona and move through space F. ________- darker , cooler spots on the sun’s surface G. ____________- huge, arching columns of gas H. ___________- violent eruptions from the sun that shoot gases outward at high speed solar wind sunspots prominences solar flares

17. 6. __________- doughnut-shaped region beyond Neptune where comets come from Kuiper belt

18. 7. ___________- a spherical region of comets that surrounds our solar system Oort cloud

19. 8. ___________- fragments in space in no particular orbit meteoroids

20. 9. _________- space fragments that enter our atmosphere and burn up meteors

23. 10. ___________- meteors that hit Earth meteorites

25. 11. _________- particles caught between the inner and outer planets (Mars and Jupiter) asteroids * Ceres is the largest asteroid at 480 miles in diameter.

26. The End