Why the moon is soundless and other fun facts: A science teacher explains
The moon is around 4.51 billion years old, give or take 10 million years. A new analysis of lunar rocks brought to earth by Apollo astronauts suggests that the moon formed 4.51 billion years ago, just 60 million years after the solar system itself took shape.
By Meenambika Menon
What are Chandrayaan 1 and 2? What do you mean by phases of the moon? And what if there was no moon? Find out the answers to these and other interesting facts about the moon, which you can share with your kids.
Is the moon a planet or a star?
The moon is neither a planet nor a star. It is the only natural satellite of our planet Earth.
How old is the moon? Which is older – earth or moon? How is the age determined?
The moon is around 4.51 billion years old, give or take 10 million years. A new analysis of lunar rocks brought to earth by Apollo astronauts suggests that the moon formed 4.51 billion years ago, just 60 million years after the solar system itself took shape. It is younger than the Earth by approximately four billion years. By dating the rocks in Earth’s ever-changing crust, as well as the rocks in its neighbours, such as the moon and visiting meteorites, scientists have calculated that Earth is around 4.54 billion years old.
The age is determined by a process called radioactive dating. By examining the existing elements, scientists can calculate the initial quantity of a radioactive element, and thus how long it took for the elements to decay, allowing them to determine the age of the rock.
How was the moon born?
It was born when a wandering planetismal crashed into the young Earth. Huge amounts of material were thrown into space, eventually coming together to form the moon. This ‘big splash’ theory would explain why the moon’s rocks are very similar to those on the earth.
How far is the moon from earth? How far is the sun?
The moon revolves around the earth in an elliptical orbit. So it gets as close as 363,104 km (225,622 miles) and as far as 406,696 km (252,088 miles). Hence, the average distance between the earth and the moon is around 384,403 km. Similarly, in an elliptical orbit during the course of a year, the earth goes from a distance of 147,095,000 km (91,401,000 mi) from the Sun at its closest point to 152,100,000 km (94,500,000 mi) at its farthest point.
Can you explain phases of the moon?
The moon itself doesn’t emit any light like the sun. What we see, when we see the moon is sunlight reflected off the moon. As the moon circles the earth, we can only see a portion of the lit up side. It is a full moon, when we see 100 per cent of the lit up side. When we can’t see any of the lit up side, it’s called a dark moon or new moon. As the moon orbits or circles the earth, the phase changes. Around once per month, every 29.53 days to be exact, the phases of the moon make a complete cycle.
How many times did man go to the moon? Who was the first? Who was the first Indian?
Twenty-four astronauts, flying on nine different missions, reached an orbit around the moon. Twelve of these astronauts walked on the moon’s surface, and six of those drove Lunar Roving Vehicles on the moon. No country other than USA has put a step on the moon. Neil Armstrong and Buzz Aldrin were the first two astronauts to leave their boot prints on the moon. No Indian has stepped on it as yet.
What are Chandrayaan 1 and 2?
Chandrayaan 1 and 2 are lunar probes sent by India to the moon. Chandrayaan 1 was launched by ISRO in October 2008, and operated until August 2009. It included a Moon Impact prober which landed on moon and gave us evidence of water on it. Chandrayaan 2 had a lander which was supposed to land on the moon and collect more data. The lander did not land softly and hence got disconnected. The orbiter is still in an orbit around the moon.
What if there was no moon?
Here are the top five things we would miss without it:
Does the moon have a dark side?
Its far side is the hemisphere of the moon that always faces away from Earth. Both sides of the moon experience two weeks of sunlight followed by two weeks of night; even so, the far side is sometimes called the “dark side of the Moon”, where “dark” is used to mean unseen rather than lacking sunlight.
Does the moon have gravity?
Yes, the moon has gravity but not as strong as the earth. Moon’s gravity is approximately 1/6th of that of Earth. This means, if a person weighs 60 kg (600 newton) on Earth then he/she will weigh just 10 kg (100 newton) on the moon. This is why the lunar astronauts could leap and bound so high in the air.
Is there wind on the moon?
There is no air to breathe or wind on the moon.
Is there water on the moon and who found it?
India’s first lunar mission in 2008 helped confirm the presence of water on the moon. Among its many achievements was the discovery of widespread presence of water molecules in lunar soil. Liquid water cannot persist at the Moon’s surface, and water vapour is decomposed by sunlight, with hydrogen quickly lost to outer space. Also there is no atmosphere on moon to hold the water vapour. However, scientists have conjectured since the 1960s that water ice could survive in cold, permanently shadowed craters at the Moon’s poles.
Short story for kids: The night the moon went missing
Some more cool facts about the moon:
(With inputs from: http://www.space.com, http://www.nasa.gov.in, http://www.isro.guv.in, http://www.esa.int, http://www.ducksters.com, http://www.insidescience.org)
(The writer is Lead, Curriculum – Science & Math at Shiv Nadar School.)
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