|
Diameter Mass mean density Surface gravity m/s^2 Escape velocity km/s |
3476.2km 7.34e18 3350 1.62 2.38 |
The moon is our nearest neighbour, it can easily be seen especially at night when sunlight can no longer reach the part of the earth which has rotated away from the Sun. Sunlight still shines at the moons surface which gets reflected towards the Earth, this makes the moon appear to glow at night.
The moon is a bit boring with being cratered and made up of rocks coloured grey. The moon lacks internal activity so no volcanoes are active; its very thin atmosphere means there is no wind on the moon so rocks that are found there have not moved an inch for millions of years.
The most interesting side of the moon is the side that you can see because there are dark regions which early astronomers imagined to be expanses of water. In fact these dark regions termed maria are around 4 billions years old and formed because the moons crust is thinner on the near side so lava flooded out from the lunar interior to fill the lowlands there. The reason why we can only see one side of the moon is because the earths gravity has caused the rotation of the moon to stop and caused the moon to orbit the Earth in a geostationary orbit.
Travelling to the moon should not be a problem if man landed on the moon in 1969 but to live there is a much bigger challenge. There is 6 million metric tons of water ice trapped at the moons poles; twice as much water ice has been detected in the north than in the south. The problem is that the water is dispersed; the moons rocky soil probably holds only 0.3% to 1% water. This means water from Earth where it is plentiful would have to be transported. This would be beneficial as it would drop the sea level of the Earth and reduce damage by tsunamis. The problem is it costs $10,000 to put 1 pound of material in orbit but Nasa is working to reduce it to $1000. It would cost $60 trillion to transport 33 million tons of water to space plus an unknown additional cost to transport it to the moons surface. This much water would be able to support a community of 1000 two-person households for well over a century without recycling.