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. AT Ancient Greece, for example, astronomers used knowledge in the field 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. At 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 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 ranging 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. Fixing exact time that it took the light to get to the moon and back, astronomers 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 full solar eclipses forever gone into the past.
Who has not stared on a clear, fine evening at the eternal companion of the Earth - the mysterious and attractive Moon? From afar, it seems even and almost white, but what is it really like, what is the distance to the moon? It is a natural satellite of the Earth, which has a spherical shape and a diameter of 3480 km. If you resort to the help of a telescope, you can see its surface, completely covered with rocks. Scientists have proven that there is no atmosphere on the Moon, which means that any life is excluded. There are a lot of hypotheses, but scientists have not yet come to an unambiguous decision. It is possible that the collected facts will gradually lift the veil of secrecy.
The distance from the Earth to the Moon, calculated between their centers, is 384,399 kilometers or 0.00257 astronomical units. If we compare it with the diameter of our planet, then the path to the satellite will be 30 Earth diameters. An interesting fact is that, unlike the Moon, it is elliptical, so the distance to the Moon periodically changes its value.
In the 2nd century, the scientist Hipparchus already knew about this property of the planet. He managed to calculate the average distance to the moon, and almost the corresponding modern meaning. He was the first to calculate that it is equal to 30 diameters of the Earth. Another scientist, in his writings "On the magnitudes and distances of the Sun and Moon" back in the 3rd century. BC tried to calculate the distances between these celestial bodies. He took as a basis the fact that the Moon has a shape close to spherical, and that it shines by light reflected from the Sun. He believed that when the moon is in a certain phase and looks like a half-disk, it forms geometric shape in the form of a triangle with a right angle. But, unfortunately, the scientist made a mistake in the calculations by 20 times, since it turned out to be impossible to determine exactly when the Moon will be located at the very top of the right angle.
Today, the distance to the moon is determined in several precise ways. Known method of triangulation of the two most distant points on Earth. Another method is based on the use of a laser and consists in the fact that the time of the laser signal sent to the moon and then received back is measured. Its essence is that on the Moon, scientists use a specially installed corner reflector. A laser signal is sent from the surface of the Earth to a reflector, and the time of its sending is precisely set. The light sent and reflected on the Moon returns to the telescope in a certain time. By calculating the exact time during which the beam traveled the distance from the Earth to the Moon and returned back, the distance from the radiation source to the reflector is determined.
For example, at the point of the orbit closest to the Earth, the distance to the Moon is 363,104 km, and when removed, more precisely at the apogee, it is 405,696 km. As a result, the distance can differ by almost 12%.
The Earth and the Moon are not point bodies, therefore, to determine the smallest distance between them, we make the following calculation: subtract the sum of the radii, which are equal to 6378 and 1738 km, from the distance at perigee. The result obtained is the required minimum distance between the points on the surface of the Moon and the Earth, which is 354,988 km.
If we set off on foot on a path equal to the distance from the Earth to the Moon, walking at a speed of 5 km / h without stopping, we would overcome it only after 9 years. An airplane flight at 800 km/h would be shorter, allowing us to land on the moon in 20 days.
In reality, American astronauts covered the distance to the moon on the Apollo spacecraft. These were the first people who walked on the moon, and this significant event took place on July 20, 1969. It took them 3 days to do this. Most fast way- is to fly at the speed of light, which is equal to 300 thousand km / s, when it becomes reachable in 1.25 light seconds.
The moon is a natural satellite of the earth. Its main influence is mainly expressed in the form of ebbs and flows, this is due to the fact that gravity creates two bulges on opposite sides of the planet. It is also located both close and far from the Earth. How long does it take to fly to the moon? Scientists had to spend a huge amount of time to calculate the optimal flight paths. Both the aircraft itself and the type of fuel used are of great importance, and the chosen take-off and landing technique also has a great influence. As a result, it may take a person from several days to eight hours to reach the surface of the satellite.
The nuances of the flight
Accurate measurement of the distance was made possible by the use of laser equipment, but even in more ancient times, the astronomer Hipparchus was able to calculate that the distance from the Earth to the Moon is approximately 380,000 kilometers, being the closest to the truth. It is the distance as well as the location celestial body are the main criteria in calculating flight duration. In search of an optimal solution, scientists have created several theories according to which it is possible to optimize the amount of fuel spent and increase the final landing accuracy.
The Moon's orbit is elliptical, which causes the distance between the satellite and the Earth to change constantly. It looks like this:
- perigee is the closest point when the satellite comes as close as possible to the planet, in the case of the Moon, the distance is from 356,400 to 370,400 km;
- apogee - the opposite point of the orbit, when the Moon, on the contrary, is most distant from the Earth, in this option the distance will be more than 404,000 km;
- the mean distance, or semi-major axis, is 384,999 km.
In order to overcome such a “small” distance by the standards of space by an airplane at a speed of 800 km / h, it will take about 20 days. It is known that the Apollo spacecraft could fly to the moon in just three days, which is already much faster. If you manage to accelerate the apparatus to the second cosmic velocity (11 km / s), then a person will be able to reach the surface of the satellite in 10 hours.
The most technologically advanced flight to the Moon was the launch of the ESA SMART-1 probe. It took him 410 days to get to the satellite. The ion engine, revolutionary for 2003, was used as a power plant, the main advantage of which was fuel economy. For the entire journey, the probe spent only 82 kilograms of fuel, securing for in a similar way the title of the most economical and at the same time the longest.
It took China's Chang'e-1 satellite five days to reach the moon's orbit using conventional rocket engines. However, he had to stay in Earth orbit for some time in order to get the correct coordinates of the point of departure. This can be considered a very good result, especially considering that this is a standard technology.
The fastest manned flight was the Apollo mission. The astronauts set off on the Saturn V and reached the lunar surface within three days. The expedition included the famous Neil Armstrong. This flight was of great importance for the United States, since the entire national idea was based on it, which required the completion of the task of conquering the Earth's satellite. Its successful implementation marked America's victory over the USSR in the space race.
However, flights can be carried out much faster. A satellite launched under NASA's New Horizons project related to the study of Pluto managed to cover 380,000 kilometers in just 8 hours and 35 minutes. This became possible due to the fact that from the very beginning the satellite had a strong acceleration of 58,000 km / h, this step was due to the task of overcoming solar gravity, which made it possible to reach the moon in a more or less acceptable time frame for humans. However, one should take into account the overloads that the body experiences during such a flight, and this, in turn, seriously complicates the whole task, making it a real puzzle for engineers.
Conclusion
However, no obstacles and difficulties could prevent the formation of travel agencies that are able to send a person into space for the weekend. There are only a few such tours, and among them there are both long ones, when ion engines are used, and fast ones, in which case the client will be returned back in just a few days. However, it should be taken into account what funds are allocated for the implementation of at least one flight. At the moment, Space is too expensive even for states, so it’s not worth talking about ordinary, even relatively rich people.
Development modern technologies proceeds at a very fast pace. Soon humanity will be able to begin colonization and the construction of long-term bases at the nearest space objects. However, the question "How long does it take to fly to the moon?" will be open due to the emergence of new, more efficient vehicles, as well as better fuel, which will provide much more energy, which will greatly increase the speed of current spacecraft.
The measurement of the distance from the Earth to the Moon was carried out in ancient times: the Greeks tried to do this repeatedly.
This information was necessary for a person to get a complete picture of the idea of the Universe.
In addition to calculating the distance to the Earth's satellite, the ancient Greeks made calculations to calculate its radius.
Over time, technological progress has developed and today all measurements are known to man.
Since ancient times, people have been interested in what the cosmos and the Moon are like - from time immemorial it has been a natural satellite of our planet.
People were interested in how far it was and how long to fly to it, using various calculations for this.
To date, to measure the distance by methods used in Everyday life- unreal.
For this, trigonometric formulas and calculations are used.
Consider how ancient people determined this indicator, recalling that it is measured from the center of the satellite:
- The first who tried to get through to the truth was Aristarchus of Samos.
On the basis of geometric equations and indicators obtained using goniometric instruments, the scientist conducted a study.
To begin with, he calculated the difference in the distance to the satellite and the Sun, after which he multiplied this result by the radius of the Earth. His calculations showed that the distance is 509680 in kilometers.
- In the 2nd century BC, the astronomer Hipparchus of Nicaea also began to calculate.
He made observations of the Moon at its various phases and came to the conclusion that the distance to the Earth would be 382,260 kilometers.
Based on angular measurements, Hipparchus found that during an eclipse, the Sun and Moon have the same indicators.
After that, he calculated the difference and derived a formula by which he determined the average distance.
Average distance in kilometers
It is impossible to indicate exact distance indicators in kilometers: this is due to the elliptical shape of the orbit along which the satellite moves.
This suggests that for some time it moves away from the planet, after which it approaches again.
Note! There are several numerical results that allow you to describe the mileage of the distance to the celestial satellite.
The actual dimensions can vary within 15%, which is associated with different satellite locations.
The fullest moon is much closer to the Earth than when it goes through its growth phase.
Known indicators will help you find out the distance that scientists have measured:
Flight time
Already done for today a large number of flights, in order to judge how long it takes to travel to the satellite.
Scientists made calculations based on the speed on the rocket and observation of the astronauts.
Here are some numbers:
- The slowest flight will take 1 year 1 month and 2 weeks, which was proved by the experiment.
In 2003, on the basis of a station with a revolutionary ion engine called ESA SMART-1, a lunar probe was launched.
- The average flight took 5 days when the Chinese satellite Chang'e-1 was sent into orbit in 2007 using standard rocket engines.
- Manned flight with a man lasted 3 days 3 hours and 49 minutes when the Americans in 1969 first set foot on the surface of the moon - spaceship Saturn 5 launched from a pad in Florida.
- The shortest path was mastered by the Americans in the New Horizons project: the speed of the satellite is 58 thousand kilometers.
To overcome the gravity of the Sun, Nasa used a huge acceleration.
Important! The Soviet satellite Luna-1 made its first flight, it passed 500 kilometers from the Moon, reaching the place in 2 days.
Today, travel space companies around the world offer trips to the Moon of short or long duration.
Any calculations made by man were surrounded by many interesting facts and stories. Measurement of space and distance to the Moon is not without such cases.
Here are some interesting examples related to the history of calculating the flight time, the distance from the Earth to the satellite:
- According to legend, the moon was formed from the collision of the planet Earth with another planet. Then an orbit was formed, from which a yellow-white satellite was formed.
- The satellite always faces the planet with one side.
- The largest crater is called Bailey, its diameter is 295 kilometers.
- During one of the expeditions, the American Apollo 6 brought several hundred kilograms of lunar soil to Earth.
- Being on the Earth and looking into the sky, it seems that the Moon and the Sun have the same size.
- There is no atmosphere on the Moon, so the night there comes immediately, without the gradual fading of light.
- The force of attraction on the satellite is the smallest - it is 6 times less than the force of attraction on Earth.
- On the surface of the satellite there is a monument to the dead astronauts - this is a figure of 10 centimeters made of aluminum.
- Over the years, the Moon has significantly moved away from the Earth: this happens every year by 4 centimeters.
- The minimum distance at the nearest points from the Moon to Mars is 55 million 399 thousand kilometers.
It is known that regular flights to Mars are planned in the future, but it is much more convenient to carry them out from the surface of the satellite.
Calculating distances to the Moon helps flight organizers to accurately calculate the amount of fuel, as well as the funds spent on the flight.
Useful video
> > > 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.