FORMATION OF THE SOLAR SYSTEM

1. FORMATION OF THE SOLAR SYSTEM Ch. 16…Pg. 552

2. Formation of the Solar System • What Galaxy are we in? • Milky Way • Alpha Centauri: Star system closest to us • Nebular Hypothesis: States that our solar system formed from Solar Nebula: A thick could of dust that began to fold in it’s own gravity into a rotating disk-shaped cloud. It’s gravity pulled heavier elements into the center, creating a protosun.

3. Section 1: Observing the Solar System Pg. 354

4. Vocab you need: • Geocentric: Earth is the center of the revolving planets and star • Greeks once believed in this formation • Heliocentric: earth and other planets revolve around the sun • What is the shape of the revolution? Elipse • Moon: Natural satellite that revolves around a planet

5. The Sun Pg. 560 • Sun is a ball of gas---not solid like the earth • Core: • Central region • Nuclear fusion(Hydrogen atoms joining together) happens here • Can only happen under high temps • Radiation Zone: Tightly packed gas where electromagnetic radiation is emitted from (Comes from) • Convection Zone: Outer layer. • Forms a convection current layer where hot gases rise, cool, then sink back down.

6. Atmosphere of the sun • Photosphere: Gives off visible light • Chromosphere: Middle layer that gives the sun it’s reddish glow • Corona: Outer layer that extends out in to solar winds (Charged particles that travel through space)

7. Planets • Terrestrial Planets: Inner Planets • Mercury, Venus, Earth, Mars • Small, dense, rocky surfaces • Jovian Planets: (Gas Giants)Outer Planets • Jupiter, Saturn, Uranus, Neptune • Large, many moons, rings (small particles of ice & rock) • Pluto: Solid surface, denser than out planets---smaller than earth’s moon • Now considered a dwarf planet

8. Comets, Asteroids, and Meteors • Comets: loose collection of ice, dust, and rock whose orbits are long narrow ellipses • Coma: atmosphere that surrounds the head of the comet • Nucleus: The inner core of the head • Gas Tail: Points away from the sun • Asteroids: Rocky objects too small to be considered planets • Orbit the sun—mostly found between Mars & Jupiter (Asteroid Belt) • Meteoroid: Chunk of rock or dust in space that has broken off of comets or asteroids. • When they enter Earth’s atmosphere, they burn, producing a tail (Shooting Star)---Meteor • Meteor shower happens when a comet passes earth, leaving a dust trail to fall into the atmosphere…

9. Chapter 17: Stars, Galaxiess and the Universe Pg. 598

10. Stars • Form imaginary patterns called Constellations • Classified by • Color: Red or Blue • Temperature: Red=Cool, Blue=Hot • Size: Sun is medium…most are smaller than that, white dwarfs are about the size of the earth • Made of: Hydrogen and Helium • Brightness: Depends on Size and Temperature • Apparent Brightness: Seen from Earth • Absolute Brightness: Brightness it would have at a certain distance from earth.

11. Measuring • Light Year: Distance light travels in one year---9.5 Million million Kilometers • Parallax: Change in position of an object when viewed from different places • Scientists use the Hertzsprung-russel diagram to classify stars. • The Main Sequence is a diagonal area where most stars exist.

12. Lives of Stars • Born a Nebula (Large cloud of Gass) • Contracts to form a protostar • Length of life depends on Mass

13. Death of A Star • White Dwarf: Blue white core left behind when a star burns out. • Supernova: Explosion that occurs when a star runs out of fuel • Neutron Stars: Remains of high mass stars where particles are left. • Black Holes: Object with gravity so high that light can’t even escape…pulls gas inward into a dense ball that can’t be penetrated

14. Star Systems • Binary Stars: Have 2 stars • Eclipsing Binaries: Systems where one star blocks the other star • Star Clusters: Larger groups of stars • Open Clusters: Disorganized appearance • Globular Clusters: Older clusters that are round and densely packed

15. Galaxies • Groups of stars or star systems • Spiral Galaxies: Spiral outward like a pinwheel • Elliptical Galaxies: Round, flat balls • Irregular Galaxies: No regular shape..smaller than other types • Quasars: Objects that are more than 10 billion light years away

16. The Milky Way • Our Galaxy • Spiral Galaxy • We are in one of the spiral arms

17. Scale of the Universe • Universe: Space and everything that is in it. • Scientific notation: Uses powers of 10 to express large numbers---Scientists use it to explain distances in space due to their large size • Look at pg. 626

18. Universe Formation • Big Bang: A tiny ball of space particles exploded. The ball was very hot and dense. The explosion caused the particles to spread out, cool, and expand. • If this is true, then the galaxy is still expanding today… • Hubble’s Law: The farther away a galaxy is, the faster it is moving away from us • Cosmic Background Radiation: Leftover energy from the big bang that creates a glow in our universe

19. Formation of the Solar System • Solar Nebula: Large cloud of gas and dust that formed our solar system. • Gravity pulled it together and pulled things toward it, causign the sun to be born. • Planetesimals: Small, planet like bodies that formed the building blocks of planets. • Inner planets: Space items pulled into sun’s gravity…water evaporated… • Outer Planets: Cooler, gasses were able to increase the size of these planets.

20. Other Characteristics • New technology and observations are leading to new discoveries every day. • Dark Matter: Does not give off light or radiation and is hard to investigate. • Dark Energy: A force that is causing the expansion of the universe to accelerate (Speed up).