How far is the earth from the moon. Ways to measure the distance from the earth to the moon in kilometers and meters and how much to fly in time. How was the distance from the Earth to the Moon calculated?

The average distance from the Earth to the Moon is usually measured between the axes of the centers of the Moon and the Earth, and this method of calculation is necessary because of the constant movement that both participants in the cosmic process make. Obeying the force of universal gravitation, the only satellite of the planet Earth and the first satellite of the solar system, if we conduct a traditional count from the luminary, then approaches, then moves away from it under the influence of multi-vector attraction. The distance to the Moon from the Earth in kilometers is a variable value determined by the periods of movement of cosmic bodies, their phases and cycles, periods of interaction.

View from the moon

Brief history

Attempts to determine the distance between the satellite and the planet have been made since the moment when a person realized that the Moon is not a hole in the solid sky through which light enters the planet at night. The well-known figure of 384,400 kilometers (384,399 km, if absolutely accurate) can be given by competent sources as a number obtained in relation to an astronomical unit.

But the average distance is the value of the semi-major axis of the moon's orbit, and it is 384,000 km. And as an astronomical unit, it is customary to take the distance from the Earth to the star, which is the center and main driving force of the solar system.

solar system

Its third planet, the first with an existing satellite, is 0.00257 AU from its satellite. The latter is also the result of complex calculations, and it is the average distance from the Earth to the Sun. The closest to the habitat of mankind, the mysterious and constantly present satellite of the planet in the night sky has always attracted the attention of man.

The moon was mysterious and incomprehensible to the primitive consciousness.

Her ability to move across the sky and change gave her mysticism and mystery, as a result of which a lot of beliefs and superstitions were born. The birth of science, the constant observation of the movements in the sky and the shadows cast on the Earth, led to reflections and calculations.

In the center of modern European and world civilization - Ancient Greece - astronomers constantly monitored the movement of shadows and the heavenly bodies themselves, which were the brightest and most dominant in the earth's sky. Astronomers of other historical periods did not lag behind them:

Aristarchus of Samos, who tried to determine with the help of a right-angled triangle at what distance the Moon is from the Earth, was mistaken by almost 29 times. This happened because the Greeks did not have the opportunity to make absolutely accurate astronomical observations.
A century later, Hipparchus of Nicaea obtained different results, using the radius of the globe as a unit of measurement. He determined the distance between the Earth and the Moon with an accuracy that boggles the imagination of modern man. Using geometry, observation of shadows, simple goniometric and optical instruments, this distance with such a minimum error (380-382 thousand km) could only be calculated by a truly brilliant scientist.
At present, it was possible to determine what the distance is with the help of a laser beam. The reflector, installed by a space mission on the lunar surface, sends out a beam of rays, some of which returns to a special detector. The main figures in this method are the speed of light and the time taken by the rays to travel the distance, and this exact method made it possible to make measurements with virtually no errors.

Earth's magnetic field

The distance calculation in modern astronomy is based on many indicators - data obtained from the earth's surface, using radio signals and laser beams, spacecraft and telescopes, computers and permanent observations.

Read also: How far is the ISS from Earth: kilometers to the space station

The celestial picture tends to constantly change, because the bodies in it make a steady movement. An object closest to the planet either leaves or returns in its elliptical orbit, so the distance can be maximum or minimum numbers.

It is believed that today human knowledge allows you to measure it with an accuracy of up to a centimeter. However, articles found in the search engine may contain variable or conflicting numbers. It is also sometimes claimed that the exact data is still unknown.

Moon orbit

On the definition of remoteness and options for its value

Wikipedia is a popular project to turn to if there is any doubt about any data. The answer to the query, what is the distance from the Earth to the Moon, contains several numbers, the average of them is 384 thousand 467 km.

The constant movement in the space of the Universe does not allow answering the question of remoteness with one general figure, therefore, knowledge of individual parameters is necessary to answer. It should be taken into account where the Moon should be in relation to the earth's surface, where it will go depending on the phase.

Planet sizes

Even the most accurate answer is not possible in real time. Because while the calculations are being made, it continues to move, as a result of which the result will undergo tangible changes.

To obtain approximate knowledge about the remoteness of the fifth largest satellite of the planets of the solar system and the only celestial body visited by man (except the Earth), you can analyze some data obtained by monitoring the Moon for many years.

Average distance from earth

Perigee

Perigee (the point of the lunar orbit closest to the third planet) under different conditions is, on average, 363,000 km. If it is absolutely accurate, then 363104 kilometers, and 000 are given to simplify the presentation.

The subject of numerous beliefs, superstitions and predictions of astrologers in the minimum value can deviate quite far from 363000 (356 thousand 400 km and 370400 are quite significant distances by earthly standards). Recently, the phases of the moon, its location, proximity or distance from earthlings, it is customary to attach great importance.

satellite view

It has become customary for people to listen to astrologers' forecasts related to the white Moon (perigee) and black (apogee, or maximum distance from the Earth), look at frightening photos, read where Mars is at this time and under what zodiac constellation are certain days of the month.

If we discard the mystical components and common superstitions, we can take the results of forecasts quite seriously as reliable data. Cosmic scales do not exclude the action of the universal gravitational force, according to which not only the Earth acts on the Moon, but also the satellite affects the processes of its main owner, and the colossal mass of the center of the solar system allows it to hold and rotate its planets together with satellites, despite the average distance in almost 150 (149.6) million km.

This is clearly shown in the table.

The figure 380 thousand km (384467 km) is the distance between the centers of the Moon and the Earth, sometimes defined as 0.00257 AU. That is, it is approximately equal to 30 earth diameters, and the value of 384399 kilometers is the semi-major axis of the elliptical orbit along which the cosmic body closest to the planet moves. At the same time, the very concept of a stable Universe cannot be taken for granted.

Our planets

Cosmos is gradually changing under the influence of multi-vector forces and mutual influences. Even the Moon moves away from planet Earth by 38 millimeters every year under the influence of gravitational-tidal acceleration, and its orbital changes range from maximum perigee to the largest apogee.

Read also: Distance from the Sun to Pluto: average in km, light years and a. e.

Apogee

This is the exact opposite of perigee, a conditional point of the lunar orbit, so they began to call it from the terminology of the ancient Greeks, which later passed into the language of science - Latin. During a complete revolution around its main center of rotation, the only earthly satellite does not make the expected circle, but an ellipse.

The apse is the name of the two points of the path being made, the pericenter and the apocenter, the nearest and the most distant, but the line of apsides can also change. The minimum value of the apogee is 404 thousand km, the maximum value is 406 thousand 700 km. It has been calculated that at different stages of the rotations made by the Moon, it can additionally move away by more than 25 thousand km.

Distance from Earth

The modern methods of measuring distance were based on a variety of methods, up to ancient Greek, the graphic representation of which has survived to this day. The accuracy of the calculations of Hipparchus, who had only goniometric tools, is amazing, but the merit of Eratosthenes, who calculated the circumference of the Earth and thereby gave the reference figure to Hipparchus, is not always mentioned.

It is no less amazing that the data on the diameter of the planet, obtained on the basis of the calculations of Eratosthenes, made it possible to come as close as possible to the figure known to date.

Watch a video on this topic.

Change in distance under the influence of time

Complex calculations are the main method for determining distances, which over time acquires volumes that frighten the common man.

The main hypothesis of the origin of a cosmic body thrown into the planet's orbit about 4.5 billion years ago is the collision of the Earth with another hypothetical planet.

Immediately after the appearance in the Earth's orbit, the Moon was about 20 times larger than the current one and was perfectly observed above the horizontal line. Scientists believe that it could be at a distance that is ridiculous for today, about 15-20 thousand kilometers. Knowing the diameter, you can easily determine the radius.

Earth's atmosphere

The Moon is an extremely curious celestial body, which is influenced not only by the Earth, but also by the Sun, as well as other components of the solar system. Even if you do not know about the hypothesis of its origin, you can assume its unusual occurrence, because it is the only satellite of our planet, and one of the largest in the solar system. However, samples of lunar soil showed a prescription of 4.1 billion years, which is much less than the date of the alleged cosmic catastrophe.

With the discovery of the theory of universal gravitation by Newton, scientific explanations appeared for numerous reasons that scientists had for many years of observation. For example, why the records of predictions of solar eclipses by famous researchers of antiquity did not coincide with their actual passage. Halley suggested that the Earth's day lengthened, and this was due to the gradual removal of the moon. To confirm the gradual flight of a natural satellite, it is sufficient to measure the distance on a continuous basis.

The minimum distance from the Earth to its satellite

Radar and laser signal reception showed that the annual removal is 3.8 cm, and by a strange coincidence, the distance between the planet and the satellite is 3.8 x 10 to the 5th km. It seems that it is not difficult to calculate how many years the Moon will leave the Earth, or that, under the influence of friction due to ebbs and flows, will turn to the satellite on one side, it is not difficult, it is enough to know simple calculation formulas.

However, it is impossible to accurately determine this time, even knowing that the year is 365 revolutions of the Earth around the Sun (because in fact there are more of them, hence the errors in the calculations, and there are exactly 36300 seconds in a day), and the speed of light is three hundred thousand kilometers.

Starry sky and earth

The approximate period of time in which it is possible to determine the probable lunar flight is 616 billion years or even more, so it’s not worth thinking especially about what will happen if ... it’s not worth it yet. It is even difficult to determine the period when there will be no solar eclipses, because the satellite will not reflect the light of the star (sun rays).

what is the distance from the earth to the moon?

The moon (lat. Luna) is a natural satellite of the Earth. The closest satellite of the planet to the Sun, since the planets closest to the Sun, Mercury and Venus, have no satellites. The second brightest comm. 1 object in the earth's sky after the Sun and the fifth largest natural satellite of a planet in the solar system. The average distance between the centers of the Earth and the Moon is 384,467 km (0.00257 AU, 30 Earth diameters).
I know that 300,000 km plus. I forgot the size of the hook.
different walks in an elliptical orbit
Right now ... let's hit the road, measure ...
The moon moves around the Earth not in a circle, but in an ellipse, so its distance from the Earth does not remain constant: 405,696 km at apogee, 363,104 km at perigee.
384,400 km. i'm bored.
moon in numbers
Average distance to the Moon 384401 km = 60.27 Earth equatorial radii
The minimum distance from the Earth to the Moon (perigee) is 356400 km
The maximum distance from the Earth to the Moon (apogee) is 406,700 km
The time it takes for light to travel from the moon to the earth is 1.3 seconds
The eccentricity of the Moon's orbit is 0.049
The average distance from the center of the Earth to the center of mass of the Earth-Moon is 4670 km
Average angular diameter of the Moon in the sky (geocentric) 31 05.2
The angular diameter of the Moon in the sky at perigee is 33 28.8
Angular diameter of the Moon in the sky at apogee 29 23.2
The magnitude of the moon on a full moon is -12.55 m
Inclination of the Moon's orbit to the plane of the ecliptic 5 8 43.4

Sidereal orbital period (stellar) 27.321661 days = 27 days 7 hours 43 minutes 11.5 seconds
Synodic (period of phase change) 29.530588 days = 29 days 12 hours 44 minutes 2.8 seconds
Anomalistic month (the period of revolution of the Moon around the Earth) 27.554550 days = 27 days 13 hours 18 minutes 33.1 seconds
The period of revolution of the line of nodes of the orbit (retrograde motion) 18.61 years
Period of revolution of the perigee point (direct motion) 8.85 years
Orbital speed of the Moon 2681 km/h = 1.023 km/s
The angular velocity of the moon across the sky is 33/hour
The daily speed of the Moon relative to the stars is 13.176358
Mean interval between two successive meridian passages

The interval between two successive passages of the meridian by the Moon is 24 hours 50.47 minutes
Apparent libration in longitude 754
Visible libration in latitude 650
The total area of the visible surface of the Moon, taking into account librations 59%
The inclination of the equator of the Moon relative to the plane of the ecliptic 1 32.5
The inclination of the Moon's equator relative to the plane of the orbit 6 41
Moon diameter 3476 km
The length of the equator of the moon is 10920 km
The surface area of the Moon is 37.96x106 km2 = 0.074 of the surface area of the Earth
The volume of the Moon is 2199x109 km3 = 2.03% of the volume of the Earth
The mass of the Moon is 7.352x1025 g = 1/81.3 of the mass of the Earth
Density of the Moon 3.341 g/cm3 = 0.606 of the density of the Earth
Acceleration of free fall on the surface of the Moon - 1.63 m / s2 = 16.5% of the earth
Second escape velocity 2.38 km/s (11.2 km/s at Earth)
Illumination of the Earth's surface from the Moon during a full moon is 0.25 lux
Illumination of the surface of the Moon from the full Earth in the sky of the Moon - 16 lux
Moon surface temperature at night - -170 - -180 C
The maximum temperature of the surface of the Moon during the day is +130 C
The temperature of the rocks of the Moon lying at a depth of 1 m (constant temperature) is -35 C
The area of sea basins on the entire Moon is 16.9% of the total area of the Moon
The area of sea basins on the visible side of the Moon (excluding librations) is 31.2% of the visible side of the Moon
Area of sea basins on the far side of the Moon (excluding librations) 2.6% of the far side of the Moon

> > > Distance from the Earth to the Moon

Distance between earth and moon: the closest and farthest distances between space bodies. Find out how many planets will fit between the Earth and the Moon in the photo.

In short, then distance from earth to moon averages 384,403 km. But it is important to know a few nuances. We used the word "medium" for a reason, because the Moon follows an elliptical path and changes distance.

The closest and farthest distance from Earth to the Moon

At the nearest point, the distance from the Earth to the Moon is 363104 km, and at the maximum distance - 406696 km. You see a difference of 43592 km, which is quite a lot. From this, its apparent size also changes by 15%. It also affects the luminosity, because it will appear 30% brighter in the full phase and at maximum approach. This moment is called a supermoon.

This video was released in 2011 to display geocentric phase, axial position angle, libration and apparent lunar diameter for a year.

But how do we even manage to determine the distance between the Moon and the Earth? Well, it all depends on the computation time. The ancient Greeks relied on simple geometric formulas. They tracked the change in shadows for a long time and guessed that it should be 108 times the diameter of the body. From this came the idea of lunar and solar eclipses.

Scientists have found that the shadow is about 2.5 times the width of the moon. The object itself has sufficient parameters to periodically cover the Sun from us. Knowing the earth's diameter and the triangle formula, they deduced the distance of 397,500 km. Not entirely accurate, but these are amazing figures for that time.

Now we use millimeter measurement - the calculation of the time for which the signal travels from the Earth to the object. Thanks to the Apollo mission, we were able to pull this off with a satellite. More than 40 years ago, astronauts installed special reflective mirrors on its surface, into which laser beams are sent from our planet. We get a weak return, but this is enough to display the most accurate number.

The speed of light is 300,000 km/s, so it takes a little over a second to cover the path. Then it takes the same amount to return. Also, this technique helped to understand that every year the satellite moves away by 3.8 cm, and in billions of years it will visually appear smaller than the star. Yes, you have to say goodbye to your favorite eclipses.

If you remember the scale of our planets (especially the gas giants), you are surprised that this can be real. To understand, let's take a look at the planetary diameters:

Mercury - 4879 km
Venus - 12104 km
Mars - 6771 km
Jupiter - 139822 km
Saturn - 116464 km
Uranus - 50724 km
Neptune - 49244 km
Total: 380008 km

The distance between us and the satellite is 384,400 km. It turns out that we also save 4392 km. What to do with the rest? Well, you can add Pluto, which extends 2092 km, as well as some other dwarf planet. Of course, physically they would not be able to rotate side by side, but the very possibility is surprising.

In an elliptical orbit, which means that at some point it will be further, and at some, on the contrary, it will be closer.

This is why 384,403 km is considered the average distance to the Moon, or, as astronomers say, is the "semi-major axis of the Moon's orbit." When the Moon is at its closest point to the Earth (perigee), we are only 363,104 km apart. And the distance from the most distant point (apogee) to the Earth is as much as 406,696 km.

It turns out that the distance from the Earth to the Moon varies within 43,592 km. It is due to this rather large difference that the moon in the night sky is of different sizes. At perigee, the Moon looks 15% larger to us than at apogee.
The difference in distances also affects the brightness of the Moon when it reaches its full phase. At the point closest to the Earth, the full moon is usually 30% brighter than at its maximum distance from our planet. When the full moon is at perigee, it is called a "supermoon".
On the video (“One year of the Moon in 2.5 minutes”) you can admire the Moon in all its changeable beauty:

A very logical question arises: how do we know how far the moon is? The answer depends on which era we are talking about. In ancient Greece, for example, astronomers used their knowledge of geometry for their calculations.
For a long time, the ancient Greeks observed shadows and found that when an object is in front of it, the length of its shadow is 108 times its actual diameter. So a ball with a diameter of 2.5 cm, placed on a stick between the Sun and the surface of the Earth, will give a triangular shadow 270 cm long.
This observation was later used to study lunar and solar eclipses. During a lunar eclipse, the Greeks noticed that the satellite was not completely covered by the shadow of the Earth, and the width of this shadow was about 2.5 times that of the Moon. During a solar eclipse, it was noted that the size of the Moon and its location at that moment were sufficient to completely block the Sun. The shadow it cast ended at the Earth, and at the same angle as the Earth's shadow, making both shadows two versions of the same triangle, just different sizes.

The Greeks concluded that the base of the larger of the two triangles would be equal to one diameter of the Earth (at that time this figure had already been calculated and amounted to 12,875 km), and its length would be 1,390,000 km. The smaller triangle will be 2.5 times wider than the diameter of the moon, and, since. the triangles are proportional, its height will be 2.5 times the height of the Moon's orbit. By connecting these triangles, the Greeks got the equivalent of 3.5 lunar orbits. By dividing the previously calculated value of 1.39 million km by 3.5, they obtained a relatively accurate distance to the Moon, equal to 397,500 km. Not bad at all for an ancient people!
Now the distance to the Moon can be calculated with an accuracy of a few millimeters. It is enough for scientists to detect how long it takes for a laser beam launched from the Earth to reach a special reflector installed on the Moon and return back.

The determination of the so-called laser location of the Moon became possible more than forty years ago, after the astronauts of the Apollo mission installed a whole series of reflectors on the surface of our satellite. A laser beam launched from the Earth is reflected from one of these reflectors and returns to our planet.

True, out of 100 quadrillions of photons launched towards the Moon, not so many return to Earth, but this is enough for a highly accurate calculation of the distance.
Because The speed of light is almost 300,000 km/s, and it takes a little over a second for a laser beam to reach the surface of the moon. It takes the same amount of time to return. By fixing the exact time it took for light to travel to and from the Moon, astronomers can then easily calculate the exact distance to the Moon at a given time.

Thanks to this method of calculating the distance, scientists have learned that the moon is slowly moving away from our planet. Every year - by 3.8 cm. And this means that in millions of years the Moon in the sky will seem smaller than it seems to us now. And in a billion years or so, the Moon will look smaller than the Sun, and total solar eclipses will be a thing of the past forever.

The decoration of the night sky, in addition to a scattering of stars, is, of course, the Moon. Due to the combination of its size and distance from the Earth, it is the second brightest celestial object and can completely obscure the solar disk during an eclipse. It is not surprising that the night luminary has been attracting the attention of mankind for more than one millennium.

If the Earth did not have a Moon, many things would have turned out differently:

days would be much shorter;
the change of seasons and climate would be characterized by instability;
there would be less pronounced ebb and flow;
the appearance of life on the planet in its present form would be in doubt.

Moon diameter

The average diameter of the moon is not too large by cosmic standards - 3474.1 km. This is approximately two times less than the distance from Moscow to Vladivostok.

Still the moon ranks fifth place in size among the natural satellites of the planets of the solar system:

Ganymede.
Titanium.
Callisto.
Moon.

But already when comparing the sizes of satellites in relation to their planets, the Moon has no equal. With a diameter of a quarter of the earth's, it takes first place. In addition, its size is larger than that of Pluto.

What is the distance from the earth to the moon

The value is not constant. On average, there are 384,400 kilometers between the centers of the planet and its natural satellite. About 30 more Earths would fit in this space, and it takes 1.28 seconds for light to travel that distance.

What if the nearest celestial body could be reached by car at a speed of 95 km/h? Given that the entire distance is about 10 circumferences of the Earth, the journey would take the same amount of time as 10 detours of the planet around the equator. That is a little less than six months. So far, the New Horizons interplanetary station has overcome the distance to the Moon the fastest, which, on its way to Pluto, crossed the satellite's orbit eight and a half hours after launch.

The moon's orbit is not a perfect circle, but an oval (ellipse), inside which is the Earth. At different points, it is located closer or farther from the planet. Because of this, when rotating around the center of mass common with the Earth, the satellite either approaches or moves away. So, the least kilometers separate celestial bodies when the night luminary is located at the place of the orbit called perigee. At the point designated as apogee, the satellite is most distant from the planet. The minimum distance is 356,400 km and the maximum distance is 406,700 km. So the distance fluctuates from 28 to 32 earth diameters.

The first close to correct estimates of the distance to the "neighbor" of the Earth were obtained as early as the 2nd century BC. n. e. Ptolemy. In our time, thanks to modern reflective devices installed on the satellite, the distance was measured most accurately (with an error of a few cm). To do this, a laser beam is directed to the moon. Then they note the period for which it will return to the Earth, reflected. Knowing the speed of light and the time it took to reach the sensors, it is easy to calculate the distance.

How to visually estimate the size of the moon and its distance from the earth

Earth's diameter is about 4 times that of the moon, and the volume - 64 times. The distance to the night luminary is approximately 30 times the diameter of the planet. To visually estimate the distance from the Earth to its satellite and compare their sizes, you will need two balls: a basketball and a tennis ball. Diameter ratios:

Earth (12,742 km) and Moon (3,474.1 km) - 3.7:1;
standard basketball (24 cm) and tennis (6.7 cm) - 3.6:1.

The values are pretty close. Thus, if the Earth were the size of a basketball, then its satellite would be the size of a tennis one.

You can ask people to imagine that the Earth is a basketball and the Moon is a tennis ball, and to show how far the satellite is from the planet on that scale. Most will likely assume a distance of 30 cm to several steps.

In fact, to show the correct distance, you have to move a little more than seven meters. So, between the planet and its satellite, on average, 384,400 km, which is about 30 Earths or 30 basketballs, respectively. Multiplying the diameter of a sports equipment by 30 gives a result of 7.2 m. This is approximately 9 male or 11 female steps.

Apparent size of the Moon from Earth

360 angle degrees- the entire circumference of the celestial sphere. At the same time, the night luminary occupies about half of one degree on it (an average of 31 minutes) - this is the angular (visible) diameter. For comparison: the width of the nail of the index finger at arm's length is about one degree, that is, two moons.

By a unique coincidence, the apparent sizes of the Sun and Moon for the inhabitants of the Earth are almost the same. This is possible because the diameter of the nearest star 400 times the diameter of the satellite, but the daylight is located the same number of times further. Due to this coincidence, among all the planets revolving around the Sun, only on Earth can one observe its total eclipse.

Does the size of the moon change?

Of course, the true diameter of the satellite remains the same, but the apparent size can change. So, The moon appears noticeably larger during sunrise and sunset.. When the night luminary is low above the horizon, the distance to the observer does not decrease, but, on the contrary, slightly increases (by the radius of the Earth). The visual effect, it would seem, should be the opposite. There is no single answer explaining the cause of the illusion. We can only say with confidence that this beautiful phenomenon owes its existence only to the peculiarities of the work of the human brain, and not, for example, to the influence of the Earth's atmosphere.

The distance between the Moon and the Earth periodically changes from maximum (at apogee) to minimum (at perigee). Along with the distance, the apparent diameter of the satellite also varies: from 29.43 to 33.5 arc minutes. Thanks to this, not only total eclipses are possible., but also annular (when the apparent size of the Moon at apogee is smaller than the solar disk). Approximately once every 414 days, the full moon coincides with the passage of perigee. At this time, you can observe the largest night luminary. The phenomenon has received the rather high-profile name of a supermoon, but the apparent diameter at this moment is only 14% larger than usual. The difference is very slight, and a simple observer will not notice the differences.

With precise measurements distance, scientists were able to detect a relatively slow but constant increase in the distance between the Earth and its satellite. The rate at which the moon is moving away - 3.8 cm per year - is too small to notice a significant decrease in the apparent size of the star. Human nails grow at about the same rate. Nevertheless, in 600 million years, the Moon will be so far away and, accordingly, reduced for terrestrial observers, that total solar eclipses will remain in the past.

It is worth noting, that the satellite of the earth, formed according to modern theory from a collision of a planet with a large object 4.5 billion years ago, was originally 10-20 times closer. However, there was no one to admire the sky, decorated with a luminary 10–20 times larger than it is now.