Page 42 - Curriculum Visions Dynamic Book

The Moon is so close and yet so tantalizingly strange and unknown. Even though we have been there and walked on it, we have done little more than literally scratch the surface of this, our natural satellite.
Some things we know about the Moon are obvious enough. The Moon is about 3,500 km across, and it is made of rock.
It orbits around us in a near circle some 384,000 km from the Earth. Each lUnar day lasts for 2 Earth weeks.
The Moon is not a true sphere (ball-shape), nor is the Earth. The Moon is flattened very slightly, although less than the Earth. The longest diametre is in the direction pointing directly to the Earth.
The Moon’s gravity
The Moon is small so it cannot have the same gravity as the Earth. Gravity on the Moon is about a sixth of that on the Earth.
Astronauts experienced this dramatically. A person weighing 80 kilograms on the Earth would weigh only 13 kilograms on the Moon. As a result, even with heavy space suits, astronauts can easily hop and skip around on the Moon’s surface.
crater A deep bowl-shaped depression in the surface of a body formed by the high-speed impact of another, smaller body.
galileo A U.S. space probe launched in October 1989 and designed for intensive investigation of Jupiter.
gravity The force of attraction between bodies.
lUnar Anything to do with the Moon.
moon The natural satellite that orbits the Earth.
orbit The path followed by one object as it tracks around another.
satellite An object that is in an orbit around another object, usually a planet.
 The Moon as seen from the GAlileo spacecraft. The distinct bright crAter at the bottom of the image is the Tycho impact basin. The dark areas are lava rock- filled impact basins (mare): Oceanus Procellarum (on the left), Mare Imbrium (center left), Mare Serenitatis and Mare Tranquillitatis (center), and Mare Crisium (near the right edge).
For the mission to the Moon see Volume 6: Journey into space.
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