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astronomymercury (Mercury ** )

Astronomy — The Planet Mercury


  • Mercury’s distance from the Sun:  36,000,000 miles
  • Length of time for one circuit around the Sun (in Earth days):  88 days
  • Length of time for one axial rotation (in Earth days):  59 days, or 2/3 of a solar circuit time
  • Diameter:  3000 miles (approximately the same size as our Moon)
  • Orbital speed:  108,000 miles per hour (hence, the name Mercury!)
  • Surface temperature range:  -300 F°  to 800 F°
  • Atmosphere: Mercury has no atmosphere.
  • Mercury is always seen in the general direction of the Sun, never more than 30° from the Sun as we view Mercury from Earth.
  • The orbit of Mercury around the Sun is tipped 7° relative to Earth’s plane of orbit around the Sun.
  • During Mercury’s formative period, it cooled too quickly to develop mobile plates on a malleable mantle.
  • The surface of Mercury has many lobate scarps (long curvi-linear, cliff-like formations).
  • Mercury has a large metallic core.
  • The Sun’s strong tidal lock on Mercury keeps the planet’s equator pointing directly at the Sun.  The equator does not deviate north or south at all.
  • Radar scientists think they detected an ice cap at Mercury’s north pole.

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