Table of contents:
- 1. First map and first audio recording
- 2. The brightness of the moon and its shape
- 3. Stone "tides", moving away of the moon and eclipses
- 4. Moonquakes and the origin of the moon
- 5. Craters and an iron lake below the surface
- 6. Exploration of the Moon and the first animals that flew around it
- 7. People on the Moon
- 8. "Fallen Astronaut" and the only person buried on the Moon
- 9. Shadows and dust
- 10. Helium-3 and the future
In the lists of the main goals of all space programs, there is necessarily an item about the Moon, followed by an item about Mars. More than 60 years have passed since the first spacecraft went to the moon, and we have not gone too far in its study. And yet, in recent years, interest in the only satellite of the Earth has increased manifold.
Largely because the moon can be used as a staging post on the way to Mars and other planets in the solar system. Let's remember the most interesting facts about the most noticeable object in the night sky.
1. First map and first audio recording
The oldest map of the moon is about five thousand years old. It was carved in stone by the ancient inhabitants of Ireland.
Sketch of the image of the Moon carved in stone (right), a schematic representation of the seas (dark spots) of the Moon (left), overlapping each other (center).
The moon is mentioned in the first recorded song. In 1860, French inventor Edouard-Leon Scott de Martinville created a ten-second recording of the French folk song Au Claire de la Lune.
The moon has always attracted our attention. From time immemorial, a bright lunar disk illuminated the way for night travelers.
2. The brightness of the moon and its shape
In fact, the moon is not as bright as we think it is. Its surface reflects in much the same way as old asphalt - only 12% of the light. Due to the presence of clouds and large spaces covered with water, our planet reflects three times better, therefore, in joint photographs of the Earth and the Moon, our satellite is often artificially brightened.
By the way, like the Earth, the Moon is not a perfect ball. Its shape is more like an egg. Scientists have repeatedly tried to understand why our satellite has such a shape. It is believed that the reason is in the shifted center of mass. It is closer to the Earth than the actual geometric center of the Moon, so the satellite stretches a little.
And this is not the only consequence of their gravitational interaction.
3. Stone "tides", moving away of the moon and eclipses
Everyone knows that the moon causes the ebb and flow of the earth's oceans and seas. But few people have heard that the earth's crust also responds to the attraction of the moon. The effect is, of course, less noticeable - just a few centimeters.
In terms of volume, the Moon is about 49 times smaller than the Earth, and in area it is larger than Africa, but smaller than Asia.
Due to the interaction with the Earth, the satellite is gradually moving away from us at a speed of about 3.8 cm per year. Nails grow at about this rate. Computer simulations showed that at the very beginning, the moon was at least ten times closer, which means that it looked ten times larger in the sky.
Today, its apparent size is nearly the same as that of the Sun. But after 600 million years, it will be so far away that total solar eclipses will no longer be possible. By the way, they say that a solar eclipse saved Christopher Columbus and his team from starvation. In 1504, Columbus predicted an eclipse, which greatly frightened the indigenous people of Jamaica, and they immediately brought food to his ships.
4. Moonquakes and the origin of the moon
There are moonquakes on the moon. Sometimes they are provoked by falling meteorites. The attraction of the Earth also plays a role. But about a quarter of moonquakes are due to satellite compression. Over the past few million years, the Moon has shrunk by 50 m. Cracks form on its surface during the compression process. All this is due to the slow cooling of the inner part of the moon. After all, once our companion was much hotter.
There are several theories about the origin of the moon. According to the simplest of them, it was formed from the matter that remained after the formation of the Earth. According to a more interesting theory, the moon just flew by, and we "picked up" it.
In recent years, the assumption is gaining popularity that two protoplanets collided a long time ago (Gaia, which eventually became Earth, and Thea), and the Moon was formed from the ejected debris.
5. Craters and an iron lake below the surface
On the side of the Moon facing us, there are about 300 thousand craters. It is a common misconception that the satellite protects the Earth from most asteroids. The moon is too small for that. It's just that there is no atmosphere or erosion on the satellite, and tectonic activity is very weak, so the craters remain forever.
The moon hosts the second largest impact crater in the solar system - the South Pole Basin - Aitken. It reaches 2500 km in width and about 8 km in depth.
Its existence was determined only in the late 1960s - early 1970s on the basis of data from the Soviet Zond-6 and Zond-8 vehicles and the American Apollo 15 and Apollo 16 spacecraft. However, it was possible to study it in more detail only by the end of the 20th century.
And not so long ago, scientists spotted a gigantic metal mass beneath it. So large (more than 2 quintillion kilograms) that it changes the gravitational field of the moon. Researchers suggest that these are the remains of a huge asteroid that fell 4 billion years ago and formed this famous crater.
Due to the fall of asteroids on the Moon, giant craters are formed, the boundaries of which make up real mountains. The highest mountain - Huygens peak - reaches a height of about 5.5 km. The surface of the satellite is covered with moon dust, on which you can ride like on a snow crust, so it's time to build a ski resort on the moon. All great achievements begin with dreams and the desire to learn something new.
6. Exploration of the Moon and the first animals that flew around it
The first spacecraft to reach the lunar surface was the Soviet station Luna-2, which fell on a satellite in 1959. In the same year, Luna-3 sent the first ever images of the satellite's reverse side. Thanks to this championship, the USSR received the right to give names to objects on the moon. This is how the Tsiolkovsky, Mendeleev and others craters appeared there, as well as the Sea of Dreams and the Sea of Moscow.
The first soft landing on the moon was successful only in 1966. It was the Soviet station Luna-9. She transmitted to Earth the first-ever panoramas of the lunar surface, measured the intensity of radiation and confirmed the meteor-slag theory of the formation of lunar soil.
Its follower - "Luna-10" - became the first station in satellite orbit. According to astronomer Dmitry Martynov, from a technical point of view, it was an unusually difficult task - in that experiment, accuracy records were broken. And also on board the device were installed special devices that broadcast the melody of the "Internationale" by radio. This year Luna-25 will go to the satellite - we will tell about it in more detail later in our material.
Just two years later, in 1968, living beings successfully flew to the Moon for the first time in history. These were two Central Asian steppe turtles. On "Zonda-5" they flew around the moon in the company of flies, beetles, plants and microorganisms and splashed down in the Indian Ocean.
7. People on the Moon
In total, 12 people have visited the moon. They are all American astronauts, and not one has descended on a satellite twice. The first was Neil Armstrong in 1969, and the last to stand on the moon was Eugene Cernan in 1972.
The crew of the last mission, Apollo 17, broke many records: the astronauts spent more than three days on the surface, collected the largest collection of lunar regolith samples and spent a record amount of time in circumlunar orbit.
In total, the Apollo missions brought 385 kg of lunar soil to Earth. Of these, 110 kg were brought by the last mission.
8. "Fallen Astronaut" and the only person buried on the Moon
A monument to the deceased American and Soviet cosmonauts has been erected on the moon. This is a ten-centimeter aluminum figurine of a man and a metal plate on which the names of Vladimir Komarov, Yuri Gagarin, Pavel Belyaev, Georgy Dobrovolsky, Viktor Patsaev and Vladimir Volkov are carved among the names of the dead American astronauts.
Due to health problems, he was never able to fulfill his dream - to become an astronaut and fly into space, but asked to bury him there. In 1998, his ashes were sent to the moon on the Lunar Prospector mission, which looked for water ice at the poles. A year later, the device fell to the surface. So Eugene Shoemaker became the first and so far the only person buried on the moon.
9. Shadows and dust
There is no atmosphere on the moon, so night falls instantly. The shadows there are absolutely black, because there is no air that would scatter the light. Astronauts who have been on the moon say that in the shadows (for example, from the lander) they saw absolutely nothing, neither their hands nor their feet.
However, shadows are not such a problem. Moon dust is much more dangerous. It smells like burnt gunpowder and sticks to everything because of the low gravity and special structure.
Astronaut Harrison Schmitt accidentally inhaled this dust when he returned aboard the Challenger, and called it "moon allergy." The symptoms are really similar: watery eyes, sore throat, want to sneeze. As laboratory experiments later showed with an analogue of lunar dust, it is capable of killing cells of the lungs and brain because of the microparticles it contains - shards of glass with sharp edges.
10. Helium-3 and the future
On our satellite you will not find gold, platinum or diamonds. But helium-3 is abundant on the Moon, a suitable fuel for the thermonuclear power plants of the future. According to some experts, its extraction can cover all the energy needs of the Earth.
We have big plans for the moon. Agencies and companies plan to assemble a permanent station in orbit. There is talk of building a station on the surface as well. Astronomers dream of building a huge telescope on the far side of the moon, which will not be interfered with by the Earth's atmosphere. Under the surface, it is proposed to create a repository of DNA and seeds of all life on the planet.
The moon is considered as a transit point on the way into space. In particular, to Mars. Therefore, scientists are actively looking for ways to extract fuel for spacecraft on the moon from the water ice contained in the lunar soil.
Its main task is to make a soft landing in the South Pole region. This is a rather inaccessible area with difficult terrain and poor lighting conditions. Temperatures at night drop to –170 ° C. Under such conditions, the station will have to operate for at least a year. For the first time in history, we will be able to explore the lunar soil in the region of the satellite's South Pole. Hooray, we're back to the moon!
This will be the first landing in Russian history since 1976.