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The Earth-Moon System

Angela loves researching new facts, especially those about science and history. She feels that knowledge is essential in growth.

The view of a half moon up close.

The view of a half moon up close.

All About The Moon

Did you know that the Latin word for moon is luna, which means "earth's little buddy?" How much do you know about Earth's Little Buddy? For instance, how little is our little buddy? It is one-fourth of the Earth's diameter and 1/81th of its mass. It's Earth's little buddy, despite not being so small. The moon is the Earth's only natural satellite, and as far as the planets' satellites or moons go, ours is the largest in comparison to the size of its planet. A natural satellite refers to a planet's moons. This phrase keeps things simple since Galileo gave our moon the name moon before others learned that other moons exist on other planets. Did I lose you there? The moon is the fifth largest satellite in the universe. If you are a statistics person, the actual diameter is 2,159 miles or 3,476 kilometers. The volume is 49 times smaller than the Earth, meaning 49 moons could fit inside the Earth.

Tidal Waves on the Moon

One of the exciting things about the moon is that there are tidal waves on land. The land around the moon's equator rises like a wave. It reaches as high as 21 inches or 55 centimeters in any given spot along the equator at least once a day.

As far as tidal waves in the water on the moon, well, I'm not sure, but just this past year, in 2009, scientists discovered water on the moon on the northern lunar pole. Six hundred million metric tons of water lie there, or as we understand, it is approximately 158 billion US gallons. One article stated that there is "enough water to fulfill all of Seattle's water needs for three years."

Since the poles are frigid, even on the moon, the water would probably be in the form of ice. How cold, you may be asking. Well, the moon's surface does not have the regulation that Earth has, and in one day, the moon will vary from 253 Fahrenheit (123 Celsius) to -387 Fahrenheit (-233 Celsius).

Is the Moon Moving Away from Earth?

Every year the moon drifts further and further away from the Earth. Scientists believe at the rate of about four centimeters or one and a half inches a year, although no one knows why. Many years ago, scientists thought that the moon was much closer to the Earth. Some believe the moon came into the Earth's atmosphere due to an explosion from Mars, and debris (known as our moon) flew towards the Earth, which is how we have the moon. Although, scientists discovered that the moon and the Earth are the same age.

We do know, though, that the same side of the moon is always facing the Earth. That means that Each Lunar Day equals one Earth Month for us. Okay, technically 27.3 days, but pretty close to a month. This difference allows the moon to always face us on the same side. This slow orbit is not as slow as you might think. The moon is orbiting the Earth at 2,288 miles per hour (3,683 kilometers per hour), slightly faster than one would travel in a car, but only slightly.

The moon is always between 225,740 miles (363,300 kilometers) and 251,970 miles (405,500 kilometers) away from Earth. The variance is because the moon moves around the Earth in an elliptical fashion, not a perfectly circular orbit. That means that you could place thirty Earths between the real Earth and the moon to make up the distance we are from the moon. They learned this by bouncing laser beams from the Earth off laser reflectors that astronauts have placed on the moon, allowing us to measure that distance.

Does the Moon Orbit the Earth?

Yes, the Earth has a gravitational pull that keeps the moon within the pull of the Earth, which is why it circles the moon, not the other way around.

Yes, the Earth has a gravitational pull that keeps the moon within the pull of the Earth, which is why it circles the moon, not the other way around.

Earthquakes and Volcanic Activity

Did you know that the moon has earthquakes? Wait? Can it be called an earthquake if it's on the moon? They are, called moonquakes, and they happen less frequently and are much less severe than those on the Earth. Tidal waves halfway under the surface cause earthquakes. These tidal waves are primarily caused by the disruptions in the distance between the Earth and the moon.

So why is the moon gray? It is simply because it is residue from a long volcanic history. You will find that the moon has a minimal amount of color to it. There is gray, light gray, dark gray, and all the shades in between, no beautiful green or blue or red, just gray. Although it is the brightest object in the night sky, the moon itself is much darker than the Earth since it does not produce its own light. The light we see off the moon is just a reflection of the sun from behind the Earth. If we were to stare at the moon and the Earth within the Universe, we would find that the Earth shines brighter than our moon. The only reason there is a full moon, half-moon, etc., is the amount of the moon that the sun illuminates. When we see the whole thing, it is because the Earth is not blocking the sun's rays on the moon; when we see less, I'm sure you get the point.

So why are there dark patches on the Earth? Due to volcanic lava! You thought I got side-tracked, huh? The dark spots are dried lava that has settled in craters on the moon. The holes were caused by meteors hitting the moon, so when lava would flow, they would fill the cavities causing dark gray matter to appear that we can see from Earth. Meteors more commonly hit the moon than Earth because Earth has such an atmosphere that most meteors that attempt to hit the Earth burn up. That doesn't mean meteors have not hit the Earth, but most were so long ago that the rain, wind, and other weather matters covered up the damage.

Oddly enough, the side of the moon facing us has more volcanic activity. The other side of the moon is much thicker, and lava is less likely to seep through. Although if we were to see that side, we would find that there are many more craters on that side of the moon than on the side we see every day. Although these craters on not filled with lava and do not appear to have the dark gray spots that we call maria.

The moon fascinates us, and we will always be thirsting to learn more about Earth's little buddy. Hopefully, soon, we, as in astronauts, will be able to take another successful journey to the moon. Who knows, maybe one is being planned as we speak if the solar system fascinates you, how about reading about black holes and the mystery behind them.


  • NASA. Accessed February 27, 2018.
  • Paulberry. "RebelMouse vs. WordPress VIP." RebelMouse. January 31, 2018. Accessed February 27, 2018.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

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© 2010 Angela Michelle Schultz


abhishek singh from mumbai on June 04, 2020:

nice one


Tim Truzy from U.S.A. on December 10, 2019:

Intriguing and great read. Some scientists believe the moon may have came to the Earth from outside of our solar system because the composition of materials on the satellite are different from what's on Earth. Who knows? But your article was a great read. Thanks.

Angela Michelle Schultz (author) from United States on September 29, 2011:

Thank you!!! I'm glad you enjoyed it!

HomerMCho on September 19, 2011:

Entertaining hub of yours, angela.

Angela Michelle Schultz (author) from United States on November 10, 2010:

Thanks for the very nice compliment! I appreciate it!

Susan Mills from Indiana on November 09, 2010:

You string words together VERY nicely.

My daughter and I loved this hub. It was informative and fun to read... a rare combination.

Thank you!

Angela Michelle Schultz (author) from United States on November 03, 2010:

Thanks! I am glad to teach you something new.

Susan Hazelton from Northern New York on November 03, 2010:

Very interesting, I did not know that the moon is drifting away from the earth. I also didn't know the meaning was 'earth's little buddy'.

Rated up and useful.

Angela Michelle Schultz (author) from United States on October 16, 2010:

Oh, I'm so sorry for all my false information. I heard that you can talk to the man on the moon and he'll help you grant your wishes. Sorry for all the erronous facts.

bayoulady from Northern Louisiana,USA on October 16, 2010:

Sorry to tell you this, but you have your facts wrong.I distinctly remember My daddy telling me in 1954 that the moon appeared to be the face of a man because all of the cheese there made shadows tha just looked like a face. he reassured me that it was only blue cheese, and I shouldn't worry. Now my daddy wouldn't lie, would he? Of course not.LOL! Seriously...Nice hub,well written and rated up!

Angela Michelle Schultz (author) from United States on October 15, 2010:

I should have written about the moons effects on the Earth. Interesting!

fred allen from Myrtle Beach SC on October 15, 2010:

Could you imagine the view of the moon as it orbited the Earth very close to the atmosphere? How about the tidal conditions that would create? Great hub!

Angela Michelle Schultz (author) from United States on October 15, 2010:

Eiddwen Thanks so much! I appreciate the nice compliment.

Eiddwen from Wales on October 15, 2010:

A briilianf hub angela. I am bookmarking it so I'll have it on hand when I need to refer to it.

Thank you so much for an original and informative hub.

Take care angela.

Angela Michelle Schultz (author) from United States on October 14, 2010:

Thanks for the great compliment. The moon is very fascinating. :)

theherbivorehippi from Holly, MI on October 14, 2010:

Oh I just love this hub!!! I shall link it to mine! The moon is so fascinating and I love when you leave stones and crystals out overnight it blesses them with so much energy. Earth's little buddy is truly powerful!

Angela Michelle Schultz (author) from United States on October 13, 2010:

Oh my goodness, you are right! I found the news article stating that. That is really neat, because everything I read either denied water being there, or saying we do not yet know. I guess it's already time to update my hub!

VagabondE from Hitting the road again on October 13, 2010:

We have found water on the moon but these are great facts. I think the moon has always fascinated mankind.

Angela Michelle Schultz (author) from United States on October 13, 2010:

DrBJ so true. There is so much of this world, and others that we do not know yet. Very exciting. There was a hub I wanted to write about a new discovery regarding Einsteins string theory, but I wasn't sure how to write it in a way that explained what I wanted to say.

drbj and sherry from south Florida on October 13, 2010:

Hi, a-m, your hub proves once again how little we (humans) really know about the earth, the moon, the planets, and the solar system.

Thanks for providing some info on what we DO know.

Angela Michelle Schultz (author) from United States on October 13, 2010:

Heart4theword, thank you so much for the great compliment! I appreciate it! I actually only learned that when studying about the moon as well. :)

Angela Michelle Schultz (author) from United States on October 13, 2010:

Very right DiamondRN. It's so coincidental that the moon and the Earth are roughly the same age. Hmmm....

Angela Michelle Schultz (author) from United States on October 13, 2010:

Makingsense, that's really interesting. I think there is truth to what you say.

heart4theword from hub on October 13, 2010:

Learned something new today:) I had heard of luna, yet never knew what the meaning was! Detail hub, was very interesting! Awesome:)

Bob Diamond RPh from Charlotte, NC USA on October 13, 2010:

Another one of God's "coincidences" that make life on earth both possible and pleasant, Angela_Michelle.

Makingsense on October 13, 2010:

I haven't heard anything about new plans to visit the moon. What's amazing is that it only took 7 years after Kennedy's "We choose to go to the moon" speech to make it happen. It provides reason for optimism that many of the challenges we face today could be successfully tackled within another 7 years.

Here's the speech:

Angela Michelle Schultz (author) from United States on October 13, 2010:

Thanks Jiberish.

Jiberish from florida on October 13, 2010:

Pamela I used to suffer from migraines until I found a wonderful Indian doctor who noticed that my migraines always occurred a day or two before or after a full moon. Instead of giving me drugs, he taught me how to avoid them. Good Hub!

Angela Michelle Schultz (author) from United States on October 13, 2010:

I'm glad to teach you something new about facts.

Pamela Oglesby from Sunny Florida on October 13, 2010:

Interesting hub with several facts I hadn't known.

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