Earth's Vital Statistics and Earth System

• Earth's Vital Statistics

  Age: 4.543 billion years old

  Equatorial circumference: 40,075 km

  Equatorial radius: 6,378 km

  Polar radius: 6,356 km

  Total mass: 5.972 x 1024 kg

  Total volume: 1.08 x 1012 km3

  Total surface area: 5.10 x 108 km2

  Average density: 5.513 g/cm3
• Troposphere


  The lowest layer of the atmosphere, extending up to 12 km (7.5 miles), where weather occurs and living things thrive
• Stratosphere


  The layer extending 50 km (31 miles) above the Earth, with a stable temperature and the Ozone Layer, which shields the planet from UV radiation
• Mesosphere


  The layer from 85 km (53 miles) to 50 km (31 miles) above the Earth, where temperature decreases gradually and meteors/space debris burn up
• Thermosphere


  The layer from 85 km (53 miles) to 640 km (400 miles) above the Earth, where aeronomical phenomena like the Northern Lights occur
• Exosphere


  The outermost layer of the atmosphere, extending 10,000 km (6,200 miles) above the Earth, where gases are lost to space
• Layers of the Atmosphere

  • Troposphere
  • Stratosphere
  • Mesosphere
  • Thermosphere
  • Exosphere
• Atmosphere


  A collective layer of gas that envelopes the earth. Essential to life on Earth because it shields the Earth from harmful ultraviolet radiation from the Sun, maintains the warmth of the Earth's surface, and contains all of the essential gases needed to support life.
• Hydrosphere


  Bodies of water that consist of freely flowing bodies of water found on the surface of the Earth, as well as water reservoirs stored below the ground as groundwater. This sphere covers 71% of the Earth's surface. 97.4% of the Earth’s Hydrosphere is composed of saline or salt water from oceans.
• Biosphere


  The narrow band on the Earth’s surface where all biological life resides. This could range from bustling cities, lush tropical rainforests, arid deserts, or even extreme environments like the bottom of the ocean floor.
• Geosphere


  Largest out of all the spheres extending from the surface of the Earth down to its center. It comprises external processes that we can observe on the surface and internal processes deep within.