Mercury

Innermost Planet of the Solar System

Proper NameMercury
Sidereal Period88 days
Mean Distance from the Sun57.9 million km
0.39 AU
Sidereal Day1,407.5 hours
Diameter4,878 km
Mean Surface Temperature+172°C
MoonsNone
Illustration of Mercury

A view of the barren, cratered world of Mercury.

Size Comparison of Mercury

With a diameter of only 4,876km, Mercury is the smallest of the terrestrial planets - less than half the size of Earth, and scarcely larger than Earth's Moon.

The second smallest of the planets in the Solar System, whose orbit carries it the closest to the Sun. Mercury is a barren, desolate world, not unlike Earth's Moon in general appearance.

Sunrise over Rodin

Sunrise over Rodin, a double crater in the northern hemisphere of Mercury. This image represents the view from within the first, larger crater: the second, deeper crater is also clearly visible.

Map of Mercury

Key features on the mapped hemisphere of Mercury.

Indexes

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