Mercury

Mercury, closest planet to the sun, revolves around it the fastest, with the shortest year in our solar system-88 days.

Mercury, named for the messenger of the gods-where speed is of the essence!

Only one spacecraft has ever visited this planet, "Mariner 10" in the mid-70's, though a new mission called "Messenger" is planned for the end of this decade.

Mercury's day / night temperature variations are the greatest in the solar system.


Chris Chyba
Carl Sagan Chair for the Study of Life in the Universe
SETI Institute & Stanford University

Mercury is so close to the Sun that it's simply uninhabitable. If it did have an atmosphere it would lose it... the solar wind from the sun, charged particles would strip Mercury's atmosphere quickly. It's just too close to the Sun and it's too small a world.

Revolution

Rotation

Radius

Distance From the Sun

88 Earth days
It revolves around the Sun the fastest, with the shortest year in our solar system.

176 Earth days

2,439.7 km

57,910,000 km

Mass

Density

Surface Temperature

Moons

0.3302 x 10 27 grams

5.43 gm/cm3

427 to -173 C
Mercury's day and night temperature variation are the greatest in the solar system.

none

Atmosphere

Craters

Volcanoes

Water

mainly argon, neon and helium

Mercury's surface is covered with craters, much like Earth's Moon

Mercury appears to have few if any volcanoes-though there's evidence of plentiful lava flows early in its history.

Mercury had water, but it boiled away to space as the planet got hot enough to melt lead
It is believed that water ice is still located in the shaded regions of its pole.

WANT TO LEARN MORE?
Missions:
 • Messenger (Launch 2004)
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Additional Links:
 • JPL's Solar System Exploration
 • The Nine Planets
 • Views of the Solar System
 • Windows to the Universe