Moon: Some astonishing facts July 20, 2009
Posted by WorldbyStorm in Moon, Science.trackback
WILLIAM REVILLE, Irish Times
Moon Facts: National Geographic News
• How did the moon form? According to the “giant impact” theory, the young Earth had no moon. At some point in Earth’s early history, a rogue planet, larger than Mars, struck the Earth in a great, glancing blow. Instantly, most of the rogue body and a sizable chunk of Earth were vaporized. The cloud rose to above 13,700 miles (22,000 kilometers) altitude, where it condensed into innumerable solid particles that orbited the Earth as they aggregated into ever larger moonlets, which eventually combined to form the moon.
• By measuring the ages of lunar rocks, we know that the moon is about 4.6 billion years old, or about the same age as Earth.
WILLIAM REVILLE, Irish Times
The moon is slowly moving away from Earth. The current distance between the Earth and the moon is 384,000km but it was closer in the past. The moon is slowly drifting away from the Earth at a rate of 4cm per year.
Daytime temperatures on the surface of the moon are about 130 degrees and night time lows reach about minus 110 degrees.
The mass of the moon is about one 80th 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 60kg on Earth, you will weigh only 10kg 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.
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. 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.
Moon Facts: National Geographic News
• The distance between the Earth and its moon averages about 238,900 miles (384,000 kilometers). The diameter of the moon is 2,160 miles (3,476 kilometers). The moon’s mass—the amount of material that makes up the moon—is about one-eightieth of the Earth’s mass.
• Because the force of gravity at the surface of an object is the result of the object’s mass and size, the surface gravity of the moon is only one-sixth that of the Earth. The force gravity exerts on a person determines the person’s weight. Even though your mass would be the same on Earth and the moon, if you weigh 132 pounds (60 kilograms) on Earth, you would weight about 22 pounds (10 kilograms) on the moon.
WILLIAM REVILLE, Irish Times
The moon takes the same time to orbit the Earth as it takes to rotate once on its own axis (27.3 days, approximately). This synchronisation causes the moon to always show the same face to the Earth. In other words, one hemisphere of the moon always faces Earth and the other (the “dark side of the moon”) always faces away.
Moon Facts: National Geographic News
• The rotation of the moon—the time it takes to spin once around on its own axis—takes the same amount of time as the moon takes to complete one orbit of the Earth, about 27.3 days. This means the moon’s rotation is synchronized in a way that causes the moon to show the same face to the Earth at all times. One hemisphere always faces us, while the other always faces away. The lunar far side (aka the dark side) has been photographed only from spacecraft.
WILLIAM REVILLE, Irish Times
We see the moon because it reflects light from the sun. The moon shape we see changes in a repeating cycle because the amount of the moon that is illuminated varies depending on its position relative to the Earth and the sun. We see a full moon when the moon is directly in front of us and the sun is directly behind us, illuminating a full hemisphere of the moon.
Moon Facts: National Geographic News
• The shape of the moon appears to change in a repeating cycle when viewed from the Earth because the amount of illuminated moon we see varies, depending on the moon’s position in relation to the Earth and the sun. We see the full moon when the sun is directly behind us, illuminating a full hemisphere of the moon when it is directly in front of us. The new moon, when the moon is darkened, occurs when the moon is almost directly between Earth and the sun—the sun’s light illuminates only the far side of the moon (the side we can’t see from Earth).
WILLIAM REVILLE, Irish Times
We see no moon when it is directly between the Earth and the sun – the sun now illuminates only the side of the moon we cannot see from Earth. Paradoxically, we call no moon the “new” moon.
The moon’s gravitational pull on the Earth is the main cause of ocean tides rising and falling. The Earth’s oceans display two bulges of water: one where the oceans face the moon and the pull is strongest; and the other where the oceans face away from the moon and the pull is weakest. Both bulges represent high tides.
Moon Facts: National Geographic News
• The moon’s gravitational pull on the Earth is the main cause of the rise and fall of ocean tides. The moon’s gravitational pull causes two bulges of water on the Earth’s oceans—one where ocean waters face the moon and the pull is strongest and one where ocean waters face away from the moon and the pull is weakest. Both bulges cause high tides. These are high tides. As the Earth rotates, the bulges move around it, one always facing the moon, the other directly opposite. The combined forces of gravity, the Earth’s rotation, and other factors usually cause two high tides and two low tides each day.
WILLIAM REVILLE, Irish Times
The moon is the only extraterrestrial object to have been visited by humans. The Soviet Union made the early running in modern investigations of the moon. Luna 2 was the first artificial object to impact the lunar surface in 1959. Luna 3 sent back pictures of the moon in 1959. Luna 9 was the first spacecraft to soft land on the moon in 1966. The first human to walk on the moon was Neil Armstrong on July 21st, 1969, on the Apollo 11 mission. Only 12 people have ever stepped onto the surface of the moon.
# The first space craft to send back pictures from the moon was Luna 3 (built by the Soviet Union) in October 1959.
Or…
The moon is the only extraterrestrial object to have been visited by humans. American astronauts Neil Armstrong and Buzz Aldrin were the first. They landed on the moon on July 20, 1969.
WILLIAM REVILLE, Irish Times
We have all amused children by pointing out the “man in the moon”, but there really is a man on the moon since 1999 – or at least his ashes are there. Dr Eugene Shoemaker, a geologist, educated the Apollo astronauts about craters.
One of his dreams was to fly a space mission but he never made it because of medical problems. After he died, his ashes were placed on board the Lunar Prospector spacecraft, which was crash-landed in a moon crater on July 31st, 1999.
The official purpose of the mission was to discover if there was water on the moon, but it also fulfilled Dr Shoemaker’s dream.
We all know there was a man on the moon, but did you know that there is one who stayed there? Dr. Eugene Shoemaker, a Geological Surveyor, who educated the Apollo mission astronauts about craters, never made it into space himself, but it had always been one of his dreams. He was rejected as an astronaut because of medical problems. After he died, his ashes were placed on board the Lunar Prospector spacecraft on January 6, 1999, which was crashed into a crater on the moon on July 31, 1999. The mission was to discover if there was water on the moon at the time, but it also served to fulfill Dr Shoemaker’s last wish.
Amazing stuff. Really. Amazing.
Recent images from NASA’s Lunar Reconnaissance Orbiter – footprints from the Apollo 14 mission: http://www.nasa.gov/images/content/369228main_ap14labeled_540.jpg
Higher res images to come on subsequent passes.
Good stuff. Interesting piece in the last or second last issue of New Scientist on whether it will be taikonauts or astronauts next on the Moon.
http://www.newscientist.com/article/mg20327162.400-apollo-special-another-small-step.html
I wonder will Madam be asking Mr Reville about the similarities. It would be ironic if, after all the rows the content of his writing has caused because of their political and moral contents, he should fall on a basic journalism standard.
References. They’re so easy to use. I’m always amazed when they’re left out.
Well spotted, WbS. Reville is pathetic. Just pathetic. Another example is the way he trots out the pro-fluoridation line of his UCC dentist colleagues. Totally unscientific. More evidence of the decline of the Irish Times.
Thanks for the photo, alastair. Will we have Google Moon to join Google Earth?
Akshully … I just realised that plagiarism is (supposed to be) a serious breach of both academic and journalistic standards.
hi peepsuiotrew’kuj7hyjiko