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The Moon

Earth’s natural satellite, the fifth largest satellite in the solar system
Average distance from Earth     384,400 km
Diameter     3,476 km
Mass     7.35e22 kg
Orbital period around Earth     27.3 Earth days
The Moon has no atmosphere or magnetic field. It is extremely large yet relatively distant from its parent planet. Other moons of the solar system tend to be classified as natural satellites or captured planetoids but the Moon does not fit into either of these categories. Most rocks on the surface of the Moon seem to be between 4.5 and 3 billion years old, older than those usually found on Earth. Thus the Moon provides evidence about the early history of our solar system.

Our Solar System

Our solar system is located on the edge of a spiral arm called Orion’s Arm, and is one-half to two-thirds of the way (28,000 light-years) from the center of our Milky Way galaxy.

The Sun, Sol

The Inner Planets
    The Moon

The Asteroid Belt
  Dwarf planet, Ceres
  Asteroid, Ida
  Asteroid, Vesta
  Asteroid, Eros

The Outer Planets

The Kuiper Belt
  Dwarf planet, Pluto
  Dwarf planet, Eris

The Oort Cloud
  Dwarf planet, Sedna
  Comet Halley
  Comet Hale-Bopp

  Glossary of Terms
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