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Closest planet to the Sun, the eighth largest planet in the solar system
Average distance from the Sun     57,910,000 km / 0.38 AU
Diameter     4,880 km
Mass     3.30e23 kg
Orbital period around the Sun     0.24 Earth years / 88 Earth days
Number of moons     0
Because of its proximity to the Sun, temperature variations on Mercury are the most extreme in the solar system ranging from –170º C (–270º F) to 430º C (800º F). Its solid surface is covered with craters and it has almost no atmosphere. There is evidence of ice in the protected shadows of craters near the north pole. Mercury is best viewed with a small telescope or binoculars during its greatest western or eastern elongation, during pre-dawn or early sunset.

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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