Chapter 1 Intro to Earth Science

1. Chapter 1 Intro to Earth Science

2. Key Ideas Earth science is the study of: Geology – study of Earth’s surface and interior (minerals & rocks) Astronomy – study of the universe & Earth’s place in the Universe Meteorology – study of the Earth’s atmosphere and weather Oceanography – study of the ocean (waves/currents/shorelines – NOT life in the oceans, that’s marine biology)

3. Origins of the Earth • Protoplanet Hypothesis – an educated guess about the origin of the Earth & Solar System based on 6 facts • all planets revolve around the sun in the same direction (counter clockwise (CCW) looking from above) • the orbits (paths) of planets are nearly circular • Most of the orbits are in nearly the same flat surface (plane)

4. Origins of the Earth • Protoplanet Hypothesis (continued) • the sun rotates on its axis in almost the same plane and direction that the planets revolve (CCW) • most planets rotate in the same direction as the sun (CCW) • most planets have moons, and their moons revolve around the planets in the same direction planets revolve around the sun (CCW)

5. What the Protoplanet Hypothesis States • Great dust/gas cloud 5 billion years ago rotated in space • Force of gravity pulled the rotating dust & gas towards the center • The cloud shrank and spun faster

6. What the Protoplanet Hypothesis States (cont’d) • Compression (squeezing) caused friction & heat between the molecules • This heat caused Hydrogen molecules to “mush” together (NuclearFusion) • This formed the sun, then the remaining dust/gas eventually formed the planets, moons & other small bodies

7. OK, so that’s how the solar system formed…but how did the Earth become what it is today? The answer is… Heat and density differences

8. Inner Core – Earth’s center made of solid iron & nickel Outer Core – layer of liquid iron & nickel Mantle – thick layer of dense rocks Crust – uppermost layer of less dense rocks (it’s thickest below mountains) Layers of the Earth