earth science 1

• Earth's structure


  Made up of four different layers, each with distinct characteristics and composition
• Core


  • Hottest layer of the Earth, source of the Earth's magnetic field
• Inner core


  • Deepest layer, made up of solid iron and nickel
• Inner core


  1,230 to 1,530 km thick, 5,000 °C
• Outer core


  • Very hot ball of metals, composed of liquid or molten iron and nickel
• Outer core


  2,200 km thick, 2,000 °C
• Mantle


  • Dense layer composed of molten silicate rocks, made of molten iron and minerals that will still flow under pressure
• Mantle


  Largest layer of the Earth, 2,900 km thick, 1000°C to 3700°C
• Crust


  • Earth's outermost layer, where life exists
• Crust


  Thinnest layer of the Earth, two types: continental and oceanic
• Earth's subsystems


  • Lithosphere
  • Hydrosphere
  • Atmosphere
  • Biosphere

  
• Lithosphere


  The rocky crust of the Earth, inorganic and composed mainly of different kinds of minerals
• Hydrosphere


  Composed of all the waters in the Earth, including oceans, seas, rivers, lakes, and moisture in the air
• Atmosphere


  Mass of air surrounding the planet, subdivided into different layers of different densities, 79% Nitrogen and fewer than 21% Oxygen

  
• Biosphere

  Comprised of all living organisms, from smallest bacteria to largest whale, including plants, animals, and single-celled organisms
• The Earth's subsystems interact with each other
• Habitable zone


  Area around a star where it is not too hot and not too cold for liquid water to exist on the surface of surrounding planets
• The distance Earth orbits the Sun is just right for water to remain as liquid</b>
• Habitable zone


  Also known as Goldilocks zone
• Water


  • One of the most important necessities to human survival, the most basic element of life
• Energy


  • The most obvious source is sunlight, which drives photosynthesis in plants
• Time


  • Habitable worlds need stars that can live at least several billion years, long enough for life to evolve

  
• Recycling


  • Happens because the outer part of the planet is made up of large moving pieces of rock, some of which sink deep down into the Earth
• Other factors for habitability

  • Atmosphere
  • Nutrients
  • Magnetic field