The Solar SystemThe Solar System

Chapter 23Chapter 23

23.1- The Solar System23.1- The Solar System

1.1. Earth-centered model-Earth-centered model- The idea that the The idea that the sun, moon, and all of the stars revolved sun, moon, and all of the stars revolved around Eartharound Earth

Who believed? Who believed? Early Greek ScientistsEarly Greek Scientists

2.2. Sun-centered model- Sun-centered model- The moon revolves The moon revolves around Earth, but all planets revolve around Earth, but all planets revolve around the Sun. around the Sun.

First proposed? First proposed? Nicholas Copernicus in Nicholas Copernicus in 15431543

3. Percent of mass Sun has of our Solar System- 3. Percent of mass Sun has of our Solar System- 99.86%99.86%

4. How solar system formed? 4. How solar system formed?

Large cloud of ice, gas, and dust began to Large cloud of ice, gas, and dust began to contract, gravity pulled matter inward, formed contract, gravity pulled matter inward, formed sun, planets formed from remaining materialssun, planets formed from remaining materials

- How long ago did it form? - How long ago did it form? 4.6 billion years ago4.6 billion years ago

5. When did sun become a star? 5. When did sun become a star? When the When the temperature of the core reached 10 million temperature of the core reached 10 million degrees Celsius.degrees Celsius.

6. 6. Nuclear fusion-Nuclear fusion- Atoms with low mass Atoms with low mass combine to form heavier elements.combine to form heavier elements.

7. 7. Inner planets:Inner planets:

1. Mercury1. Mercury 2. Venus2. Venus

3. Earth3. Earth 4. Mars4. Mars

Another name? Another name? Rocky or TerrestrialRocky or Terrestrial

8. 8. Outer Planets:Outer Planets:

1. Jupiter1. Jupiter 2. Saturn2. Saturn

3. Uranus3. Uranus 4. Neptune4. Neptune

Another name? Another name? Gas or Jovian PlanetsGas or Jovian Planets

9. Shape of planets’ orbit: 9. Shape of planets’ orbit: ellipticalelliptical

Who discovered this? Who discovered this? Johannes Kepler in Johannes Kepler in 1600’s1600’s

23.5 Other Objects in Space23.5 Other Objects in Space

1.1. Comet-Comet- a large “dirty snowball” that a large “dirty snowball” that circles the suncircles the sun

How long does it take Halley’s comet to orbit How long does it take Halley’s comet to orbit the sun? the sun? about 76 yearsabout 76 years

2. What are comets comprised of? 2. What are comets comprised of?

Frozen gases, ice, and dust particlesFrozen gases, ice, and dust particles

3. 3. Oort Cloud-Oort Cloud- a large collection of comets a large collection of comets surrounding the solar systemsurrounding the solar system

Located? Located? Beyond Pluto’s orbitBeyond Pluto’s orbit

4. 4. Meteoroid-Meteoroid- piece of rock moving through piece of rock moving through spacespace

Meteor-Meteor- meteroid that burns up in Earth’s meteroid that burns up in Earth’s atmosphereatmosphere

Meteorite-Meteorite- meteor that strikes Earth’s meteor that strikes Earth’s surfacesurface

5. What are meteors commonly called? 5. What are meteors commonly called? Shooting starsShooting stars

6. 6. Asteroid-Asteroid- piece of rock smaller than a piece of rock smaller than a planetplanet

- Between what two planets is the - Between what two planets is the asteroid asteroid beltbelt? ? Mars and JupiterMars and Jupiter

How do scientists suspect it formed? How do scientists suspect it formed?

- - Strong gravitational tugs from Jupiter kept Strong gravitational tugs from Jupiter kept a planet from forminga planet from forming

7.Kupier Belt 7.Kupier Belt hundreds of icy objects hundreds of icy objects beyond the orbit of Neptunebeyond the orbit of Neptune