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Mercury




Symbol
Diameter4880 km, 0.38 x Earth's
Mass0.06 ME
Average Distance from Sun58 x 106km = 0.387AU
ColourGrey
TemperatureDay: 430°C
Night: -183°C
AtmosphereNone
Length of Day58.65 days
Length of Year88 days
No. of MoonsNone
Gravity0.376 x Earth's



Craters on the surface of Mercury Mercury is the closest planet to the Sun and the second smallest in our Solar System. Only one spacecraft has ever been there. It was called Mariner 10, and took pictures of the surface of the planet. It found that Mercury is a rocky planet, covered in craters like the Moon. These craters are made when chunks of rock from outer space called meteorites smash into the surface. The biggest of these craters is 1300km across and is called the Caloris Basin.

Mercury has the biggest difference in temperatures in the Solar System. In the middle of the day, the temperature gets up to about 430 C, and at night it drops to 183 C.

Mercury doesn't have an atmosphere because it was blown off by a stream of particles from the Sun called the solar wind.

The planet has a very large amount of iron in its centre. This is surrounded by a layer of rock, which makes up the surface that we see.





Planets Introduction

Venus

Earth

The Moon

Mars

Jupiter

Saturn

Uranus

Neptune

Pluto

Asteroids

Comets

Meteorites

Extra-Solar Planets



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Authors: Carolyn Brinkworth and Claire Thomas

Last updated: July 2001