Formation Theories

1. Formation Theories Pg.

2. Collapsing Interstellar Cloud • Stars and planets form from clouds of gas and dust (interstellar clouds) • Can start to condense due to gravity and become concentrated enough to form a star or planet • Astronomers hypothesize that this is how our solar system formed

3. Sun and Planet formation • The disk of sun and gas that formed the Sun and planets is called the solar nebula • Rings formed around the Sun and spun, eventually condensing to form solids and liquids • Once condensing from the Sun slowed, the tiny particles merged together and collided with other particles • As the debris got larger, it formed planetismals • Not all debris was collected during formation

4. Asteroids • Leftovers from the formation of the solar system • They are pitted and have irregular surfaces

5. Pieces of Asteroids • When pieces of asteroids break and enter Earth’s atmosphere they are called meteoroids • Earth’s atmosphere burns the meteoroid and leaves a streak of light called a meteor. • If it doesn’t completely burn, parts hit the surface and are called meteorites

6. Comets • Small, icy bodies that have highly eccentric orbits around the Sun • Made of ice and rock • Closest comet cloud is next to Pluto • When a comet gets close to the Sun it evaporates and becomes bright and forms a head and tails • The head consists of the coma (glowing gas) and the nucleus (small solid core)

7. Kepler’s Third LawPg. • Use Appendix J (pg.921) to calculate the orbital period for the eight planets in our solar system. • P = a , where P is the orbital period in years and a is the semimajor axis in AU • Create a table like the one below and fill in • Answer #’s 5 and 6 on page 791