Elizabeth Russell, age 9, of Newport News, Va., for her question:
Do scientists think the moon came from the Pacific Ocean?
The Earth has had a moon for countless ages. And long ago our cavemen ancestors began to wonder how it got up in the sky. Wise men in every generation have wondered haw it was created. And even the clever scientists of our generation are not sure how the moon was born.
The golden moon is our nearest neighbor in the sky, and we know a great deal about it. We know that it orbits the Earth and that each trip around takes a little longer than 27 days. We know how far away it is and that its distance varies between 226,000 and 252,000 miles. We know that it is a round ball and that our globe is almost four times wider than the moon.
We know that the moon has a history. It was not always there, so it must have had a birthday. But we are sure that it was created in the dim, distant past. The experts know many facts about our golden moon, but they are not certain how it was created. When scientists meet a puzzling question, they gather facts and more facts. Each fact is tested and proved before it can be accepted as true. We do not stop searching for an answer until every fact has been proved many times.
Astronomers are still searching for more facts about the birth of the moon. Some experts think that it may once have been part of the Earth. Others think that the moon and the Earth were never joined together as one. These educated guesses are theories, and no one can say for certain how the moon was born because we do not know enough facts.
Most experts suspect that the planets and their moons were formed from leftovers from the sun. They think that our starry sun shrank from a whopping cloud of gases and left solid fragments of material whirling around it. In time these fragments joined together to form the large planets and their orbiting moons. Perhaps the moon was formed in this way.
Another theory suggests that at first the Earth was much bigger and very restless. Its cooling crust may have been shaken by furious upheavals. These upsets may have been strong enough to tear the young planet in two parts. If this did happen, the smaller section may have whirled off to become the orbiting moon. The Pacific Ocean fills a monster hole in the Earth's crust. The experts who suspect that the moon was once part of the Earth think that it may have been torn from this deep basin in the Pacific. But no one can prove that this is true.
According to one theory the moon is a sister of the Earth. If this is so it was formed from material that gelled together soon after the sun was born. Another theory suggests that the moon is a daughter of the Earth, torn from the deep basin that now holds the Pacific Ocean. Another theory suggests that the moon is the Earth's prisoner. In the past it may have been a planet with its own orbit around the sun. It could have passed too close and been captured by the Earth's gravity.