Here are some of the essential facts about Earth:

• Radius    6378 km
  
  
• Rotation    23 hours 56 minutes sidereal
  
  
• Revolution    1.00 years to orbit the Sun
  
  
• Semi major axis    1.00 A.U. by definition
  
  
• Atmosphere    Mostly Nitrogen with a significant amount of oxygen. Very strange for a terrestrial planet. Small amounts of carbon dioxide and water vapor, just enough to make for interesting weather. An atmospheric pressure equal to 1.0 bar.
  Unique atmospheric structure with vertical air movements in the troposphere. The ionosphere is a charged layer that reflects radio waves.
  
  
• Surface Features    Oceans continents, mountain ranges oceanic ridges and trenches, all unique to Earth. Earth does has a few notable impact craters, including Barringer Crater in Arizona. Here I am at the crater's rim.
  
  
• Magnetic field    Earth has a fairly strong magnetic field generated by our outer core of liquid iron.
  
  
• Natural Satellites Just one natural satellite called the Moon.
  
  
• Space Probes Earth has been circled by hundreds of probes since the late 1950's, all launched by human beings, hoping to find out more about the planet which they call home.

Back to previous page.