Earth Science 1

721 views
529 views

Published on

Published in: Technology, Education
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
721
On SlideShare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
10
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide
  • -x and y axes-2-4 billion; how long?-
  • Earth Science 1

    1. 1. Origins of the Earth<br />
    2. 2.
    3. 3. Objectives: you should be able to…<br />1. Define hypothesis<br />2. Explain the protoplanet hypothesis<br />3. Explain how the earth’s oceans and atmosphere might have formed<br />*proto = “earliest”, or “original”. What do you think proto-planet might mean?<br />
    4. 4. What is a hypothesis? <br />An educated guess, but….<br />A good hypothesis should: <br />Explain known facts<br />
    5. 5. Known facts<br />1. All planets revolve around the sun in the same direction<br />2. The orbits of the planets around the sun are all nearly circular.<br />3. Most of the orbits are in nearly the same plane. <br />4. The sun rotates (turns on its axis) in the same direction as the planets.<br />5. Most planets have moons, which revolve in the same direction as the planets. <br />
    6. 6. Protoplanet hypothesis<br />5 billion years ago…<br />A cloud of gas and dust rotated in space<br />The cloud began to collapse… why?<br />Gravity<br />Explosion of passing stars<br />Shrinking made the compressed cloud rotate faster.<br />Compression made the interior very hot<br />
    7. 7.
    8. 8. Protoplanet hypothesis, cont’d<br />The center of the compressed gas cloud became hot and eventually, the core became the sun.<br />Hydrogen fusion<br />~10% of the cloud formed a disk surrounding the sun<br />Friction within the disk caused most of the mass to collect into eddies. <br />These eddies were compacted and became planets and moons. <br />
    9. 9. Review<br />1. Define hypothesis<br />2. Explain the protoplanet hypothesis<br />3. Explain how the earth’s oceans and atmospheres might have formed<br />
    10. 10. Protoplanet hypothesis <br />An enormous, rotating gas cloud begins to collapse<br />Most of the material collects in the center, eventually becomes the sun<br />What compressed the gas? Gravity, explosions<br />Other, smaller, gas & dust masses shrank into protoplanets.<br />
    11. 11. video<br />
    12. 12. How did the oceans form?<br />When the earth formed, there was no ocean<br />Compression, radioactive minerals, and meteorite showers made the earth hotter.<br />The heat melted the iron, which sank toward the center of the earth, and formed a core.<br />The iron melted other materials that it touched, releasing water and other gases.<br />The steam escaped to the surface in volcanic eruptions.<br />
    13. 13.
    14. 14. How did the atmosphere form?<br />What’s in the atmosphere?<br />78% Nitrogen<br />21% Oxygen<br />1% others (including CO2)<br />Gases from volcanic eruptions: NO FREE OXYGEN!<br />Break up of H20 molecules by sunlight<br />Plants added oxygen through photosynthesis<br />
    15. 15. Objectives<br />1. Define hypothesis<br />2. Explain the protoplanet hypothesis<br />3. Explain how the earth’s oceans and atmosphere might have formed<br />

    ×