DARK SKIES: Our lunar satellite fascinates
OUR nearest neighbour in space is the Moon.
Varying between 356,000km to 415,000km from Earth, the Moon has fascinated humans for countless centuries with its light and phases.
On any full Moon night, out in the rural sector its light is so bright one can almost read a newspaper, whereby in cities with thousands of street, commercial and industrial lighting, moonlight is not as impressive.
The moon takes 28 days, 12 hours, 44 minutes and 2.8 seconds to make one orbit around the Earth at 3683km/h.
During this time it travels 2,290,000km.
During this lunar cycle, the Moon goes through various phases from a new Moon - when it lies between the Sun and Earth - to a half-shaped Moon (first quarter) to full, to last quarter and then back to new Moon.
Since the Moon keeps the same face to Earth as it orbits our planet, anyone out in space looking back at the Moon and Earth would see the Moon rotate on its axis in exactly the same time it takes to orbit Earth.
On its dusty, grey-coloured surface where one lunar day and night is equal to 14 Earth days and nights, the Moon is constantly bombarded by micro- meteors - tiny particles of space rock pounding the surface into a fine, talcum powder-like dust. This was first reported in the mid-1960s when NASA purposely crashed its Ranger probes into the surface to measure the ground hardness, prior to the Apollo 11 moon landing on July 20, 1969.
Ranger probes not only found the surface to be quite hard, the lunar surface dust averaged 2.5cm deep and not tens of meters deep as first thought.
NASA has now mapped the Moon on both sides to 1m resolution using its Lunar Remote Orbiting Camera - LROC probe.
So clear are these images they show all the astronauts' footprints and scientific gear left behind by the Apollo 11 - 14 landing missions.
This gear now monitors the Moon's orbit, distance and geological status. Every second, 24/7, the Moon is bombarded with deadly gamma and UV rays from the Sun that would cook you instantly if you removed any part of your protective spacesuit.
Lunar temperatures vary from 120C in sunlight to -170C at night. Lunar craters range from a few metres to a 1200km monster crater on the far side. The lunar 'seas' are dark-grey hardened basalt - cooled lava that flowed over the surface 4.5 billion years ago.
LROC has found small craters on the tops of mountains and dozens of deep lava tubes that could house humans from the dangers of space.
On the far side of the Moon, a future array of radio telescopes would pick up clearer and more distant sounds from interstellar space. With no interferences from noise chatter from Earth, it would be quite possible to pick up the tell-tale sounds of another solar system.