# How Far Is The Moon From The Earth?

gsenviro | College Teacher | (Level 1) Educator Emeritus

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The moon is a satellite of planet Earth. The moon revolves around the Earth in an elliptical orbit, which means that the moon-Earth distance is not constant: it changes depending on the moon's location in the orbit.

After careful measurements, it has been found that at its farthest point in its orbit (apogee), the moon is about 405,000 kilometers away from Earth. In comparison, at the nearest point in its orbit (perigee), the moon is about 360,000 kilometers from the earth. Thus, on average, moon-Earth separation is about 382,500 kilometers.

Before the first lunar mission took place, the distance was calculated by a study of planetary motion or by using a telescope.

Astronauts then left glass reflectors on the surface of the moon, and very precise distance measurements could be carried out by determining the time it took light to reflect back from these reflectors.

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mrbakertheteacher | Elementary School Teacher | (Level 1) Valedictorian

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Astronomers during the Apollo missions placed mirrors on the surface of the earth so that scientists can fire a laser beam to the moon, wait for the beam to reflect off of the mirrors and return to earth. Because they know how fast a laser beam travels, they can calculate the distance within centimeters.  They found that when the moon is closest to earth it is 363,104 km (225632 mi) away. When it is at it's furthest point away it is 405,696 km (252,099 mi) away. The average distance away is 384,393 km (238,854 mi) away.

ajprincess | Student, Grade 10 | (Level 1) Valedictorian

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It is approximately 384,405 km away.................................

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Are you wondering how far is the Moon from Earth? Well, the exact number is an average of 384,399 km, or 238,854 miles.

This number is an average because the Moon takes an elliptical orbit around the Earth. Sometimes it’s closer than this average number, and other times it’s more distant. At its closest point, called perihelion, the Moon measures 363,104 km from the Earth. And then at the most distant point of its orbit, known as aphelion, the Moon is 405,696 km from Earth. This is a big difference: 42,592 km.

Because of this huge different in difference, the size and brightness of the Moon can change dramatically when the full Moon matches up with a close Moon. It can be 15% larger and 30% brighter than an average Moon.

You might be surprised to know that astronomers have actually measured how far the moon is from Earth to within a few centimeters. They’re able to do this because the Apollo astronauts left small reflective mirrors on the surface of the Moon during their last mission. Astronomers on Earth fire a laser pulse at the Moon and measure how long it takes to hit the Moon, bounce off the reflectors and return to Earth. By knowing the speed of light, and timing the return journey of the light pulse, they’re able to calculate the distance to the Moon with incredible accuracy.

fact-finder | (Level 3) Valedictorian

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Since the moon's orbit is elliptical (oval-shaped), its distance varies from about 221,463 miles (356,334 kilometers) at perigee (closest approach to Earth) to 251,968 miles (405,503 kilometers) at apogee (farthest point). The average distance from the moon to the Earth is 238,857 miles (384,392 kilometers).

Sources: McGraw-Hill Encyclopedia of Science and Technology 7th ed., vol. 5, p. 470; The Universal Almanac 1992, p. 16.

academy633 | College Teacher | (Level 1) Salutatorian

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What should be noted is that the moon is gradually, very gradually, moving away from the earth.  Tidal friction is not only slowing the earth's rotation, but is draining energy from the moon's motion.See http://curious.astro.cornell.edu/question.php?number=124  for a complete explanation.

Also, did you know that the earth-moon system is a double planet, and the only one in our solar system.  The moon's orbit around the sun is always concave relative to the sun, unlike every other planetary satellite in the solar system.  The moon's mass is much greater relative to the earth than the same ratio of other satellites to their solar system planets.  And the paths of all other satellites exhibit retrograde motion, but our moon doesnot!   We are living on a double planet!

crazynitin1998 | Student, Grade 9 | (Level 1) Salutatorian

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when the moon is closest to earth it is 363,104 km away. When it is at it's furthest point away it is 405,696 km  away. The average distance away is 384,405 km  away.

isks149 | Student, Grade 9 | (Level 1) Honors

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Well, the exact number is an average of 384399 km, or 238854 miles.

troubleshooter | (Level 1) eNoter

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The distance to the Moon is actually slowly increasing!

Over millennia, the gravitational pull of the tides are pulling on the Moon and transferring energy.  The Earth is loosing energy, and the Moon is gaining energy!  This is slowing the rotation of the Earth, and speeding up the Moon.  This causes the Moon to move away from the Earth, and our days to become longer!

See:
http://en.wikipedia.org/wiki/Orbit_of_the_Moon#Tidal_evolution

The distance to the Moon increases by 38 mm per year[1] and our days are increasing about 15 microseconds every year[1]. (This is not a fixed rate and will change in the far future as the Earth slows and the Moon recedes).

[1]
http://en.wikipedia.org/wiki/Moon#Tidal_effects

Mr KL

lnj100 | Student, Grade 10 | (Level 1) Valedictorian

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The distance varies somewhat, during the course of a month and also during the course of a year.

It averages out to about 93 million miles.

The moon's average distance from the sun is the same as the earth's average distance from the sun. When you think about it... the moon orbits around the earth, so it's closer to the sun half the time, and farther from the sun half the time... averaging out to the same distance from the sun as the earth is.

In any case, the moon averages 238,000 miles from the earth, which is less than 1/4 million, and that doesn't make much difference compared to the 93 million average between the earth and the sun... less than 1/4 of 1 percent.

inneedofhelp3550 | Student, Grade 11 | (Level 1) eNoter

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They found that when the moon is closest to earth it is 363,104 km (225632 mi) away. When it is at it's furthest point away it is 405,696 km (252,099 mi) away. The average distance away is 384,393 km (238,854 mi) away. Or alternitivly, very far away.

crazynitin998 | Student, Grade 10 | (Level 1) Salutatorian

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when the moon is closest to earth it is 363,104 km away. When it is at it's furthest point away it is 405,696 km  away. The average distance away is 384,405 km  away

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The distance between the Moon and the Earth varies from around 3,56,400 km to 4,06,700 km!!

pororohandy | Student | (Level 1) Valedictorian

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The moon is 384,403 kilometres away from the earth !!!!!! The moon's orbit is not a perfect circle, it is an ellipse; So the distance isn't constant ... there is a minimum and a maximum. The distance fluctuates between 363,104 kilometers and 405,696 kilometers (225,622 to 252,088 miles) due to the eccentricity of the Moon's orbit

myfavouritehero | Student, Grade 10 | (Level 1) Honors

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Moon is at a distance of about three lakh and eighty five thousand (385,000)kilometers from Earth.

crystaltu001 | Student, Grade 10 | (Level 1) Valedictorian

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The distance from the moon to the earth is 384,400 km which is also equal to, 238,900 miles. But there is a chance the distance can change because the moon orbits around the earth and from different locations it may take a different amount of time to get from the earth to the moon.

nisarg | Student, Grade 11 | (Level 1) Valedictorian

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238,900 miles is the average distance but it fluctuates with each month. This motion of earth's only satellite causes the tides to rise and fall on the surface of the earth. The moon also slightly affects the earths orbit. At the furthest it is about 405,000 km away from earth

taangerine | Student, Grade 12 | (Level 1) Valedictorian

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The moon is approximately 384,399 km, or 238,854 miles, away from the Earth.

rachellopez | Student, Grade 12 | (Level 1) Valedictorian

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According to NASA, the average distance from Earth to the Moon is 382,500 kilometers. However, the distance may vary because the Moon orbits around the Earth. When the moon is closet to the Earth, which is called perigee, it is about 360,000 kilometers away. When it is furthest away from earth, which is called apogee, the moon is about 405,000 kilometers away.

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zumba96 | Student, Grade 11 | (Level 3) Valedictorian

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The Moon from the Earth is 238,900 miles away which is 384,400 km.

laurto | Student, Grade 10 | (Level 1) Valedictorian

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The Moon takes an elliptical path around the Earth, which means that the Earth can get closer and further away. The average distance is 384,403 km. At its closest point, it is only 363,104 km and at its most distant point it is 406,696 km. In other words, it is very, very far but it is sometimes closer and sometimes further than the average.

amysor | Student, Grade 10 | (Level 1) Valedictorian

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According to most experts, the Moon is approximately 239,900 miles (384,400 km) away from the earth.

briceyboi | Student, Grade 10 | (Level 1) eNoter

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It's around 360,000km away from Earth or 290,000 miles away. Basically it's far away

arrellbelle | Student, College Sophomore | (Level 1) Valedictorian

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The length from the moon to the earth would approximately be 238,900 miles or 384,400 kilometers.

karlalicious | Student, Grade 10 | (Level 1) Honors

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How Far Is The Moon From The Earth?

*238,900 miles (384,400 km) Moon, Distance to Earth*

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