• Age: 4.6 billion years
• Diameter: 3,480 km
• Temperature on surface: Varies from -233 °C to 122°C
• Distance from the Earth: About 386,200 km
• Satellites: None

It is therefore sunlight that enables us to see the enormous craters on the Moon. This pockmarked surface is often referred to as the lunar surface from the word luna, which is Latin for moon. The Roman moon goddess was also called Luna while the Greeks called their moon deity Selene.

The Moon has no atmosphere, no seasons and no life. The lack of atmosphere means there is no weather and no wind, so the footprints left by the Apollo Space Station astronauts will remain for centuries.

The dark areas on the Moon are known as maria (Latin for seas) or mare (singular) because they resembled bodies of water. They were formed by lava from once active volcanoes.

The light parts are cratered highlands known as terrae (Latin for lands), the original crust of the Moon. Space Station Meteoroids, Space asteroids and Space comets have all contributed to its jagged landscape. The largest crater is the South Pole Aitken Basin, at 2,500 km wide.

The Dark Side

The moon rotates on its axis as it orbits the Earth. Because both the rotation and orbit are similar, about once every 28 days, we only ever see one side of the Moon facing the Earth.

The hidden, dark side of the Moon can never be seen by Space Station astronomers on Earth without the use of orbiting space craft mission. But this does not mean it is literally dark. A more accurate description is that is the far side because it is simply the side farthest away from the Earth.

Eclipses

A total eclipse occurs when the Moon’s, Solar system orbit brings it between the Earth and the Sun, and the Moon covers the Sun in its entirety. This causes areas of the Earth to darken during daylight beneath the Moon’s shadow.

In lunar eclipses the Earth is between the Sun and the Moon and the Earth’s shadow falls on the Moon, making it appear red.

Phases

The Moon presents different shapes - or phases - in the night sky: from a thin silver crescent to a full bright circle. These phases are called new moon, first quarter, full moon and last quarter. A new moon is when the Moon’s sunlit side is away from the Earth.

When the moon changes from new to full it is said to be waxing. When less and less can be seen, from full to new moon, it is waning. It is a crescent moon when smaller than a half moon and gibbous when larger.

Tides

The Moon’s, Space Station gravity is only 1/6th (17 per cent) that of Earth’s which is why astronauts on the Moon can bounce along the surface because a human being’s weight has decreased by 5/6th (83 per cent).

This weak gravitational force is still enough to produce tides on Earth because of the Moon’s proximity to our planet. High (spring) tides take place at new or full moon. Low (neap) tides occur when the Sun and Moon are at right angles and pulling against each other.

Origins

The most popular theory about how the Moon was formed is the giant impact hypothesis - where the Earth collided with another planet around 4.6 billion years ago – shortly after our Solar System formed.

The impact produced molten rock from the Earth which combined with the other planet to form the Moon.

Missions

The space Station race between the Soviet Union and the United States culminated in the first Apollo Moon landing on 20 July, 1969. Humans last walked on the lunar surface in 1972 (Apollo 17) but there has been renewed worldwide interest in recent years, with lunar orbiters from Japan, the USA, Europe, China and India.

An American spacecraft mission, Clementine, found the first evidence for water ice at the poles in 1994. Lunar Prospector also found strong evidence for ice in the late 1990s.

UK scientists were involved in the European SMART-1 Space mission, launched in 2003, and are also contributing to India’s first mission to the Moon, Chandrayaan-1 and NASA’s Lunar Reconnaissance Orbiter.