Interesting Facts About the Moon
Professor William Reville, University College Cork.
Origin of the Moon.
It seems that the young earth had no moon, but soon after the earth formed a Mars-sized rogue planet struck it a huge glancing blow. A large chunk of earth and most of the rogue planet were vaporised into a cloud that rose over 22,000 km in altitude where it condensed gradually into the solid moon. Lunar rocks are about 4.6 billion years old – about the same age as the earth and the composition of lunar rocks is very similar to rocks on earth.
The Moon is Slowly Moving Away from Earth.
The current distance between the earth and the moon is 384,000 km but it was closer to earth in the past. The moon is slowly drifting away from the earth at a rate of 4 cm per year. Daytime temperature of the surface of the moon is about 130 degrees C and night time lows reach about minus 110 degrees C.
Gravity on the Moon.
The mass of the moon is about one eightieth of the earth’s mass. Since the force of gravity at the surface of the object is proportional to the object’s mass and size, the force of gravity on the surface of the moon is only one sixth the force on the surface of the earth. Your weight is the force that gravity exerts on your mass. Your mass remains the same whether you stand on earth or on the moon, but if you weigh 60 kg on earth, you will weigh only 10 kg on the moon. Alan Sheppard hit a golf ball on the moon in 1971 and drove it 400 yards using a makeshift six-iron and encumbered by a heavy space suit.
Atmosphere on the Moon.
The gravity on the moon isn’t strong enough to hold an atmosphere and the moon’s atmosphere is very tenuous and insignificant compared to earth’s atmosphere. The sky always looks dark from the moon because there is no atmosphere to scatter light. Also the moon is always silent as sound waves travel through air.
The Moon Always Shows the Same Face to Earth.
The moon takes the same time to orbit the...