MERCURY.                 

 

Size: Diameter: 4,880 km

Mass: 3.32x10²³ kg                      

Distance from the sun: 57.9 million km

Distance from Earth: Max. 221 million km

Atmosphere: Thin mixture of helium and hyrogen

Composition: Rocky planet

Moonns/satellites: None

Average temperature: 452°C

Orbital period: 88 Earth days

Rotation period: 59 Earth days

Colour: Dark grey

Other facts: Mercury is the closest planet to the Sun and the fastest orbiting it. It is also the planet with the most extreme temperature ranges.