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Mercury

Mercurius

The smallest planet in our solar system and closest to the Sun. A world of extremes, where scorching days give way to freezing nights. Its cratered surface resembles our Moon, bearing witness to billions of years of cosmic impacts.

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Diameter

4,879 km

Distance

57.9 million km

Orbital Period

88 days

Day Length

58.6 Earth days

Gravity

3.7 m/s²

Temperature

-180°C to 430°C

Moons

0

Discovery

Known since ancient times (2nd millennium BCE)

Atmosphere

Exosphere — oxygen, sodium, hydrogen, helium, potassium

Exploration Missions

Mariner 10 (1974-75)MESSENGER (2011-2015)BepiColombo (2025 arrival)

Interesting Facts

  • A year on Mercury lasts just 88 Earth days
  • Mercury has no atmosphere to retain heat, causing extreme temperature swings
  • Its large iron core makes up about 42% of its volume
  • Mercury has a magnetic field about 1% as strong as Earth's
  • The planet's wrinkles — lobate scarps — formed as its interior cooled

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