stem11 gen math

• There are 7.8 billion on the total number of the world's population and over 7 million species of plants and animals
• The Earth is the only planet which is the third on its distance from the sun
• The Earth is the only place we know of so far that's inhabited with living organisms
• Identified planets in the solar system

  • Mercury
  • Venus
  • Earth
  • Mars
  • Jupiter
  • Saturn
  • Uranus
  • Neptune
• Inner planets


  The four planets closest to the sun: Mercury, Venus, Earth, Mars
• The name Earth is at least 1,000 years old
• All of the planets except for Earth were named after Greek and Roman gods and goddesses
• The word Earth came from the Anglo-Saxon or English-German word "erda" and its Germanic equivalent "erde" which means ground or soil
• Earth is the only planet in our solar system that does not come from Greco-Roman mythology
• Earth's core


  Molten nickel-iron core which gives rise to an extensive magnetic field
• The magnetic field along with the atmosphere shields us from harmful radiation coming from the sun
• Factors that make a planet habitable

  • Temperature
  • Atmosphere
  • Energy
  • Nutrients
• Temperature


  Influences how quickly atoms and molecules move
• Earth's atmosphere


  Serves as the earth's blanket that shields the surface from harmful radiation and provides chemicals needed for life
• Energy


  The capacity to do work
• Nutrients


  Used to build and maintain an organism's body
• Life seems limited to a temperature range of minus 15 degrees Celsius to 115 degrees Celsius
• Earth's atmosphere is composed of 78 percent nitrogen, 21 percent oxygen, and 1 percent other gases
• The hydrosphere is the part of the earth which circulates among oceans, continents, glaciers, rivers, and waterfalls
• Geosphere


  The solid part of the earth, from its core to its crust
• Atmosphere


  The gas mixture that forms around the earth
• Biosphere


  All life forms that exist on earth
• The sun is the main source of energy that reaches the earth's surface
• Energy enters the biosphere as sunlight
• Photosynthesis


  Plants change light energy into chemical energy
• Energy and matter flow through the earth's subsystem
• Earth is considered habitable because it is the right distance from the sun, protected from harmful solar radiation by its magnetic field, kept warm by insulating atmosphere, and has essential components for life including water and carbon
• Earth is different from other planets in that it is the only planet with liquid water on the surface
• Four spheres of Earth

  • Hydrosphere
  • Atmosphere
  • Geosphere
  • Biosphere