The moon issolar system5th largest in medium volumesatellite, its averageradiusAbout 1737.10 km, equivalent toearth0.273 times the radius;The quality is close to 7.342 × 10²²Kg, equivalent to 0.0123 times of the earth[1]。The surface of the moon is covered with impact craters that may have been formed by the impact of small bodies.The Moon andearthThe average distance is about 384400 kilometers, about 30 times the diameter of the earth.
The moon has a fluid outer core and a solid core similar to the earth.[24]
On April 21, 2024, the world's first high-precision《1: 2.5 million lunar geological atlas》Officially released。[33]The atlas was drawn by the Chinese scientific research team, mainly based onChang'e ProjectScientific exploration data is the most accurate monthly geological "photo collection" at present.[34]
The moon belongs to the earthNatural satellite, probably formed about 4.5 billion years ago, shortly after the formation of the earth, there are several originshypothesis, which is supported by more factual evidence, is that it was formed inearthAndMarsCelestial objects of the same size --“theia ”The "big collision origin theory" is formed by the accumulation of debris generated by a huge collision between the two regions around the earth.
The full moon seen from the northern hemisphere of the earth
There are a lot of darkvolcanoThe huge impact crater filled by the ejected basalt lava flow forms a vastplain, called“Moon Sea”In fact, there is not a drop of water in the "Moon Sea".There are bright, ancient anorthosite highlands and striking impact craters on the periphery of the moon sea and between the moon sea.It is in the sky exceptsunlightThe brightest celestial body outside, although it appears very bright white, its surface is actually very dark,reflectivityOnly slightly higher than the old asphalt.Because the moon is very prominent in the sky, plus the regularphase of the moonSince ancient times, changes have been associated with human cultureMyth and legend、religious belief、Philosophical thought, calendar compilation, literature, art, customs and traditions, etc.
LunarrotationAndrevolutionThe cycles of are equal (calledTidal locking ）Therefore, the moon always faces the earth on the same side.Earth OceantideIt is mainly due to the gravity of the moon.Because of thetideThe force is opposite to the direction of the earth's rotation. The earth's rotation is always subject to an extremely weak force to "brake" the earth's rotation, which has accumulated for a long time. There is sufficient evidence that the earth'sRotation periodMore and more slowly, the time of a day increases very slowly, about 1 second in a few years;Due to the reaction force of the earth, the moon is slowly getting farther and farther away from the earth, about 3.8 cm away from the earth every year.The ratio of the size of the moon to the sun is similar to that of the distance, making its apparent size almost the same as that of the sunsolar eclipseWhen the moon can completely cover the sunTotal solar eclipse。
Geological map of the moon
The moon is the first extraterrestrial land ever landed by human beingscelestial bodies。1958U.S.AandFormer Soviet UnionEmittingLunar probeAll declared failure.In 1959, the former Soviet Union and the United States successfully launched the "Luna" and "Pioneer" lunar probes respectively.In 1969, Apollo 11 of the United States achieved the first manned lunar landing, followed by Apollo 12, 14, 15, 16 and 17. A total of 12 American astronauts landed on the moon to carry out scientific investigation, collect lunar samples and bury scientific instruments for long-term lunar exploration. A total of 381.7 kg of lunar samples were brought back to the earth, greatly increasing mankind's understanding of the origin of the moonKnowledge of evolution.So far, only these 12 American astronauts have landed on celestial bodies outside the earth.
Photos of Apollo landing on the moon
In April 2018,NASAA video made from data collected by lunar orbiters was released.The data in this video is composed ofLunar Reconnaissance Orbiter(LRO) took nine years to collect.Since June 2009, the probe has been observing the moon at a distance of 50km above the lunar surface, capturing unprecedented details on the lunar surface.
Launched by China at 10:26 on January 3, 2019Chang'e-4 probeIt successfully landed in the pre selected landing area near 177.6 degrees east longitude and 45.5 degrees south latitude on the back of the moon. The world's first close-up image of the moon back was transmitted back to the earth through the "Queqiao" relay star, which opened the mystery of the ancient moon back.[2]
Node month27.212 220 relative to the ascending intersection point
The diameter of the moon is 1/4 of the average diameter of the earth, its mass is only 1/81 of the earth, and its gravity is 1/6 of the earth.
Orbital motion
Announce
edit
revolution
The moon orbits the earth in a circular orbit.This orbital plane iscelestial sphereBig circle scale cut from the top“Bai Dao”。Whiteline plane does not coincide withCelestial equatorIs not parallel to the ecliptic, andspatial location Changing.The period is 27.32 days.Moon orbit (white road) pairEarth orbitThe average inclination of the ecliptic is 5 ° 09 '.But it is known that the moon leaves the earth at an average speed of 3.8 cm every year.
rotation
The moon is circlingEarth revolutionThe cycle is 27.32166 days, which is exactly oneSidereal monthSo we can't see the back of the moon.This phenomenon is called“Synchronous rotation ”, or "tidal locking", is almost a universal rule in the world of solar system satellites.It is generally believed that it is the result of long-term tidal action of satellites on planets.LibrationIt is a very wonderful phenomenon, which enables us to see 59% of the lunar surface.The main reasons are as follows:
(1) In different parts of the elliptical orbit, the rotation speed does not match the common angle speed.
(2) The intersection angle of Baidao and the equator.
The moon moves half a degree per hour relative to the background sky, that isApparent diameterSimilar.Unlike other satellites, the lunarTrack planeCloserEcliptic surface, not on EarthEquatorial surfaceNearby.Relative to the background sky, the time required for the moon to circle the earth (the moon revolves) is calledSidereal month；The new moon is the same as the next new moon (or twophase of the moonThe time required is called aNew Moon。New moon comparisonfixed starThe length of the month is because the earth itself has advanced a certain distance in its orbit around the sun during the lunar movement.
nutation
The orbital plane of the moon（White pavement）AndEcliptic surface(the orbital plane of the earth) maintained 5.145396 °included angleAnd the lunar rotation axis is 1.5424 ° with the normal of the ecliptic plane.Because the earth is not completely spherical, but is relatively bulged at the equator, the white road surface is constantlyPrecession(that is, the intersection with the ecliptic rotates clockwise), completing one cycle every 6793.5 days (18.5966 years).During this period, the included angle between the white plane and the earth's equatorial plane (the earth's equatorial plane inclines to the ecliptic plane at 23.45 °) will vary from 28.60 ° (23.45 °+5.15 °) to 18.30 ° (23.45 ° - 5.15 °).Similarly, the included angle between the lunar rotation axis and the white track surface will also be between 6.69 ° (5.15 °+1.54 °) and 3.60 ° (5.15 ° - 1.54 °).These changes in the lunar orbit will in turn affect the tilt angle of the Earth's rotation axis, causing it to swing ± 0.00256 °, which is callednutation。
Libration
Because the rotation period of the moon is exactly the same as its revolution period, the earth can only see the moon always facing the earth with the same face.Since the early days of the moon, the earth has been affected bymomentThis process is calledTidal locking 。Therefore, part ofearth rotationThe angular momentum ofangular momentumThe result is that the moon is away from the earth at a speed of about 38 mm per year.At the same time, the rotation of the earth is becoming slower and slower, and the length of a day increases by 15 microseconds every year.
When you look at the moon from the earth, the surface of the moon is not exactly half of it. This is because the moon swings like a balance.Observers on the earth will feel that the moon swings back and forth in the north-south direction during the moon's orbit around the earth, that is, it swings like a balance in the direction of dimension, which is called "latitudinal libration", with an angle range of about 6 ° 57 ';The phenomenon that the moon swings back and forth in the east-west direction, that is, in the longitude direction, is called "libration through the sky", and the swing angle reaches 7 ° 54 '.In addition to these two major librations, the moon has Sunday librations andPhysical librationThe first three kinds of balance movements are not the swing of the moon, but the phenomenon caused by the change of the relative position between the observer and the moon.Only the physical libration of the sky is the swing of the moon itself, and the swing is very small.
becauseLunar orbitIt is oval when the moon is inPerigeeIts rotation speed will not catch up with the revolution speed, so we can see that the eastern part of the lunar surface reaches 98 degrees east longitude, on the contrary, it is atApogeeThe rotation speed is faster than the revolution speed, so we can see the area of 98 degrees west of the lunar surface.This phenomenon is called libra movement.Also, because the lunar orbit is tilted to the Earth's equator, when the moon moves in the sky, the polar region will shake about 7 degrees. This phenomenon is called libration.Moreover, since the distance between the moon and the earth is only 60 earth radius, if the observer observes from the moon rising to the moon setting, the observation point will have a displacement of earth diameter, and the area with longitude of 1 degree on the moon surface can be seen more often.
The gravitational force exerted by the moon on the earth istideOne of the causes of the phenomenon.The orbit of the moon around the earth is a synchronous orbit, the so-calledSynchronous rotation Not strictly.
Strictly speaking, the Earth and the Moon revolve around the samecentroidOperation, common centroid distanceGeocentric4700 km (i.eEarth radius3/4 of).Since the common center of mass is below the earth's surface, the movement of the earth around the common center of mass seems to be "shaking".Seen from the sky above the earth's south pole, the earth and the moon rotate clockwise;And the moon also moves clockwise around the earth;Even the earth revolves clockwise around the sun. The reason for this phenomenon is that the earth and the moon have the same relative to the sunangular momentum, that is, "from the beginning, it turns in this direction".[4]
Looking at the Earth from the Moon
The birth of the moon
Announce
edit
Discussion on the cause of formation
The origin of the moon is different.There are roughly three schools of origin of the moon in history.In the later period, on the basis of various theories and combined with new research results, a new "big collision theory" was formed.
Split theory
This is the first hypothesis to explain the origin of the moon.As early as 1898, a famous biologistDarwin's sonGeorge Darwin In the article Tide and Similar Effects in the Solar System, it was pointed out that the moon was originally a part of the earth. Later, because the earth was rotating too fast, some materials on the earth were thrown out. These materials separated from the earth and formed the moon. The big hole left on the earth is the Pacific Ocean.
This view was soon opposed by some people.They believe that it is impossible to throw such a big thing out at the speed of the earth's rotation.Moreover, if the moon is thrown by the earth, the material composition of the two should be the same.But by right“Apollo 12”The rock samples brought back from the moon by the spacecraft were analyzed and found to be very different.The age of the rocks on the surface of the moon is extremely old. The age of the rocks on the surface of the whole moon is between 3 billion and 4.2 billion years. The age of the oldest rocks on the surface of the earth is only limited to the 3.8 billion year old metamorphic rocks exposed in some areas, while the age of the rocks on the bottom of the Pacific Ocean is extremely young, which completely contradicts the theory of "splitting".
Capture theory
The assumption is that the moon was originally justsolar systemOnce, an asteroid the size of the moon was captured by the gravity of the earth when it moved near the earth, and it never left the earth again.There is also a view close to the capture theory that the earth continuously accumulates the materials entering its own orbit, and as time passes, more and more things are accumulated, eventually forming the moon.However, it was also pointed out that the earth may not have the power to capture a planet as big as the moon.
Cognate theory
This hypothesis believes that the Earth and the Moon are both diffuse nebular matter in the solar system, almost in the sameSolar nebulaThe region of.In the process of accretion, the earth is a little faster than the moon and becomes "brother".This assumption has also been challenged by objective facts.Through laboratory analysis of rock samples brought back from the moon by the Apollo spacecraft, the average chemical composition of the earth and the moon is very different, and people found that the rocks of the moon are also much older than those of the earth.
Collision theory
This hypothesis believes that in the early evolution of the solar system, a large number of“Star Child”First formed a celestial planetesimal equivalent to 0.14 times the mass of the earth, and the planetesimals formed aPrimitive Earth。These two celestial bodies formed iron based metal nuclei andsilicateThe mantle and crust.Because these two celestial bodies are not far apart, there is a great chance of meeting.[5]
A chance, that small object hit the earth at a speed of about 5 kilometers per second.The violent collision not only changed the movement state of the earth, making the earth's rotation axis tilt, but also caused the small celestial body to be hit and broken, the silicate shell and mantle were heated and evaporated, and the expanded gas flew away from the earth with a large amount of crushed dust at a great speed.These materials flying away from the earth are mainly composed of the mantle of collision bodies.The vast majority of the earth that was hit by a huge impact was also the material in the mantle and crust that was heated and evaporated. The expanding gas flew away from the earth with a large amount of crushed dust at a great speed.When the impactor ruptured, the metal core separated from the mantle decelerated due to the expansion of the flying gas, and was accreted to the Earth in about four hours.The gas and dust flying away from the earth are not completely separated from the earthgravitationControl, combine through mutual accretion to form an almost molten moon, or form a ring first, and gradually accrete to form a partially molten moon.This version is generally accepted.
This model clearly explains that compared with the average composition of the earth, the moon is relatively poor in iron and volatile matter, and its density is lower than that of the earth.The isotopic composition of some elements with the characteristics of "gene" comparison between the earth and the moon, such as oxygen, chromium, titanium, iron, tungsten, silicon, etc. The measured values of the moon and the earth are consistent within the error range, indicating that the moon is the "daughter" of the earth.For 4.5 billion years, the earth has been carrying its own daughter around, while the moon has also been accompanied by its own mother, experiencing a long and ancient age of 4.5 billion years.
Collision theory
structure characteristics
Announce
edit
brightness
The moon itself does not shine, only reflectssunlight。The brightness of the moon varies with the angular distance between the sun and the moon and the distance between the earth and the moonBottom chordMore than ten times larger.[6]
The average brightness of the moon is 1/465000 of the solar brightness, and the brightness varies from 1/630000 to 1/375000.The average brightness of the full moon is - 12.7, etc.Its average illuminance to the earth is 0.22Lux, equivalent to the illuminance of a 100 watt electric lamp at a distance of 21 meters.The lunar surface is not a good reflector, its average albedo is only 9%, and the rest 91% is absorbed by the moon.The albedo of the moon sea is lower, about 7%.Lunar highland andCraterThe albedo of the mountain is 17%, which looks brighter than the moon sea.[6]
The distance from the moon to the earth is about 1/400 of the distance from the earth to the sun, so the moon is as big as the sun from the earth.
moon
atmospheric environment
Because there is no atmosphere on the moon, and the heat capacity and thermal conductivity of the lunar surface material are very low, the temperature difference between day and night on the lunar surface is very large.In the daytime, the temperature of the moon surface in the place where the sun vertically shines is as high as 127 ℃;At night, its surface temperature can be reduced to - 183 ℃.The temperature in the lunar soil can be measured by radio observation. This measurement shows that the temperature in the deeper part of the lunar soil rarely changes, which is due to the low thermal conductivity of the lunar material.
Hierarchy
It is known from the propagation of lunar seismic waves that the moon also has layered structures such as crust, mantle and core.OutermostLunar shellThe average thickness is about 60~64.7 km.Below the moon shell to a depth of 1000 kilometers isLunar mantleIt takes up most of the volume of the moon.[6]
Below the lunar mantle isMonthly checkThe temperature of the lunar nucleus is about 1000~1500 ℃, so it is likely thatmeltIt is speculated that Fe-Ni-S andEclogiteMaterial composition.[5]
Earth moon relationship
The earth and the moon revolve around each other, and the two celestial bodies circle the commonGravitational centerRotate.The birth of the moon has added many new things to the earth.
While the moon revolves around the earth, its special gravity attracts the water on the earth, which moves together with the moon to form tides.Tide is an early aquatic life on the earth. It helps a lot when it moves to land.
Long long ago, the temperature difference between day and night was large, and the temperature wasboiling pointIt is not suitable for human beings to live between the freezing point and the freezing point.However, the special influence of the moon on the earth's seawater slows down the earth's rotation, making the earth's rotation and revolution cycle more reasonable, bringing us precious four seasons, reducing the temperature difference, and making it suitable for human habitation.
The reason why the earth sees half of the moon is that the rotation period and revolution period of the moon are strictly equal.Let's take a look at the conditions of the satellites of other planets in the solar system. We can find that the rotation period and revolution period of most satellites are strictly equal. It seems that there seems to be some internal connection.
Under the long-term action of the earth's gravity, the moon's center of mass is no longer in itsGeometric center, but on the side close to the earth, so the moon is relative to the earthGravitational potential energyIt will become the smallest, circling the earth on the moonrevolutionIn the process, the center of mass of the moon always faces the side of the earth, as if the earth tied the moon with a rope.This is also true of other satellites in the solar system, so it is not a coincidence that the rotation period and revolution period of satellites are equal, but there are internal factors.
Does the earthquake have anything to do with the moon?This is a problem that has puzzled scientists for nearly a hundred years.Today, the Japanese Institute of Disaster Prevention Science and the United StatesUniversity of California, Los AngelesA joint research team composed of researchers from, has finally confirmed that the lunar gravity affects the tide of sea water. When the crust undergoes abnormal changes and accumulates a lot of energy, the lunar gravity is likely to be the trigger for earthquakes between the earth plates.On October 22, the famous American journal Science published their research results.
The natural fluctuation of sea water is often called tide.When the moon reaches near the earth (calledPerigee）When,Looking forward to the spring tideIt is even larger than usual. The spring tide at this time is called perigee spring tide.
Scientists havetideThe impact of earthquakes has been speculated for a long time, but no one has demonstrated its impact on the global scale. Previously, only the seabed orvolcanoThe earthquake and tide are clearly related only when they occur nearby.The researchers found that the occurrence of earthquakes is closely related to the tidal pressure on the fault surface. The strong tide exerts enough pressure on the shallow fault surface to trigger earthquakes.When the tide is large, about 2-3 meters, 3/4 of the earthquakes will occur. The smaller the tide, the less likely the earthquake will occur.
Elizabeth Gowland, the author of the article, said: "The influence of the moon's gravityseawaterThe earth itself is also deformed under the action of the gravity of the moon.The violent tide has played a great role in the process of earthquake initiation, and the time of earthquake occurrence will be advanced or delayed due to the pressure fluctuation caused by the tide. "
Another author of this articleUniversity of California, Los AngelesJohn Weida, professor of the Department of Earth and Space Sciences, said: "The cause of earthquakes is still a mystery, and this theory can be said to be one of the explanations. We found that the force generated by the change of sea level within a range of several meters will significantly affect the probability of earthquakes, which is a solid step for us to thoroughly understand the causes of earthquakes."
Gochilan et alphaseThe data of earthquake and tide pressure are statistically analyzed. The calculation method adopted is from Seismologist Tanaka of Japan Institute of Geoscience and Disaster Prevention.Tanaka investigated the location, time and other records of 2207 so-called "reverse fault type" earthquakes from the global inter plate earthquakes with a magnitude of 5.5 on the Richter scale between 1977 and 2000, as well as the relationship with the lunar gravity when the earthquakes occurred,When the gravity of the moon causes the fault to be dislocated, more earthquakes occur.
Tanaka thought: "The gravity of the moon can only lead toearthquakeIt is about one thousandth of the force of abnormal crustal changes, but its role cannot be underestimated. It isearthquakeThe last help that happened was equivalent to the last straw that crushed the camel. "[6]
Eclipse phenomenon
lunar eclipseIt is a special astronomical phenomenon.It refers to that when the moon moves behind the earth's shadow, the sunlight is blocked by the earth.
That is to say, the sun, the earth and the moon are exactly (or almost) in the same straight line at this time, so the light from the sun to the moon will be covered by the earth.
For the Earth, when a lunar eclipse occurs, the direction of the sun and the moon will differ by 180 °.It should be noted that since the orbits of the sun and the moon in the sky (called the ecliptic and the white path) are not on the same plane, but have an intersection angle of about 5 °, only when the sun and the moon are located near the two intersections of the ecliptic and the white path, can they be connected into a straight line to produce lunar eclipse.
Moon
Eclipse can be divided intopartial lunar eclipse、lunar eclipseTwo (no annular eclipse, because the earth is larger than the moon).When only part of the moon enters the Earth's umbra, there will be a partial lunar eclipse;When the whole moon enters the Earth's umbra, there will be a total lunar eclipse.as forPenumbral eclipseIt means that the moon only skims over the penumbra of the earth, resulting in a slight decrease in the brightness of the moon surface. It is difficult to see the difference with the naked eye, so it is not noticed by people.
The diameter of the moon is about 3476 kilometers, about 1/4 of that of the earth.In the lunar orbit, the diameter of the Earth's umbra is still 2.5 times that of the moon.So when the center of the earth and the moon are roughly in the same straight line, the moon will completely enter the earth's umbra, resulting in a total lunar eclipse.If only part of the moon is always covered by the Earth's umbra, that is, only part of the moon enters the Earth's umbra, a partial lunar eclipse will occur.Not on the moonAnnular lunar eclipseBecause the moon is much smaller than the earth.
The diameter of the sun is much larger than that of the earth. The shadow of the earth can be divided into umbra and penumbra.If the moon enters the penumbra area, the light of the sun can also be obscured. This phenomenon is called penumbra lunar eclipse in astronomy.Because the sun is still very strong in the penumbra area, the luminosity of the moon surface is only slightly weakened, and in most cases the penumbra eclipse is not easy to be distinguished by the naked eye.Generally, it is not known aslunar eclipseTherefore, there are only two types of lunar eclipses: total lunar eclipse and partial lunar eclipse.
Eclipse and solar eclipse
In addition, since the Earth's umbra is much larger than the Moon's, this also means that the Moon will completely enter the Earth's umbra in the event of a total lunar eclipse, so an annular eclipse will not occur.
The number of lunar eclipses per year is generally 2, up to 3, and sometimes none.Because in general, the moon either passes above the Earth's umbra or leaves below, rarely passing through or partially passing through the Earth's umbra, it will not happen in generallunar eclipse。
According to the statistics of observation data, the percentage of penumbra lunar eclipse, partial lunar eclipse and total lunar eclipse in each century is about 36.60%, 34.46% and 28.94%.[7]
A binary moon
February 2024In the morning of August 8, Venus, Mars and the moon will perform the "double star moon" phenomenon in the southeast low altitude.[31]
topographic features
Announce
edit
MoonThere are dark parts and bright areas on the surface. The bright areas are highlands, and the dark areas are depressions such as plains or basins, which are calledLunaandMoon Sea。When early astronomers observed the moon, they thought that the dark areas were covered by sea water, so they called them "sea".The famous ones are the Sea of CloudsWet sea、Sea of TranquillityEtc.The bright part is the mountains, where the mountains are crisscross and dotted everywhereCrater, namely, impact crater, which is a low-lying form of circular uplift.There are more than 33000 impact craters on the moon with a diameter of more than 1000 meters.The diameter of Bailey impact crater near the South Pole is 295km, which canHainan IslandPut it in.The deepest isNewtonThe impact crater is 8788 meters deep.In addition to impact craters, there are also ordinarymountain range。High mountains and deep valleys overlap to create a unique scenery.
The structure of the back side of the moon is quite different from that of the front side.The moon sea occupies less area, while the impact crater is more.The terrain is uneven. The longest and shortest radii of the moon are located on the back. Some places are 4 kilometers longer than the average radius of the moon, and some places are 5 kilometers shorter (such as Vandergraf depression).Not found on the back“Mass tumor”。AbaxialLunar shellIt is thicker than the front, the thickest part is 150 kilometers, while the thickness of the front moon shell is only about 60 kilometers.
Impact crater
The name of the crater isGalileo Galilei It started.yesLunar surfaceThe remarkable features of the moon cover almost the whole moon surface.The largest impact crater is Bailey Crater near the South Pole, with a diameter of 295km, which is a little larger than Hainan Island.The small crater may even be a hole of tens of centimeters.There are about 33000 with a diameter of no less than 1000 meters.Occupy the lunar surfaceSpecific surface area7%~10% of the total.
A Japanese scholar put forward a classification of impact craters in 1969, which can be divided into Cravis type (ancient impact craters are generally unrecognizable, and some impact craters have central peaks) and Copernicus type impact craters.Young impact craters often cause a large number of rocks on the lunar surface to splash around, and a large number of rock fragments ejected and rolled at high speed on the lunar surface, changing the original topography of the lunar surface and the structure and color of the surface soil, forming obvious“Radial striation”The inner wall is generally provided with concentric circular segmental mounds, and the center is generally provided withCentral peak。The types include Archimedes type (with low ring wall, which may evolve from Copernicus type), bowl type or dimple type (small impact pits, some of which are less than 3 meters in diameter).
Crater
Fourteen ten thousand households named after Chinese peopleCraterZu Chongzhi, Bi Sheng, Cai Lun, Zhang Yuzhe, Shi Shen, Zhang Heng, Gao Pingzi, Shen Kuo, Liu Hui, Song Yingxing, Pei Xiu, Xu Guangqi
Other scenery
The Chang'e-3 landing land was named as "Ziwei", "Tianshi" and "Taiwei" respectively.
Chang'e-4 landed on the land named Tianhe Base, surrounded by three triangular circular pits, named Zhinu, Hegu and Tianjin respectively;The central peak in Von Carmen crater where the landing point is located is named Mount Tai.
Chang'e V landed on the land and was named as the Tianchuan Base, and the mountain peaks were named as Huashan Mountain and Hengshan Mountain
Chang'e Ring Mountain, Jingde Ring Mountain (male), Wanyuyue Stream and Songmeiyue Stream,
There are two theories about the formation of impact crater: "impact theory" and“volcanoSay ".
“Impact theory”It means that the moon has an impact crater seen by humans today due to the impact of other asteroids.
For human beings on earthnaked eyeThe dark part of the moon is actually the vast plain on the moon.Due to historical reasons, this name has been retained.
There are 22 confirmed moon seas, in addition, there are some landforms called "moon seas" or "moon like seas".The 22 most recognizedThe front of the moon。There are 3 on the back and 4 on the edge.The monthly sea surface area on the front is slightly more than 50%, of which the largest“Storm ocean”It covers an area of about five million square kilometers, about the total area of nine France.Most of the moon seas are roughly circular and elliptical, and most of them are enclosed by some mountains around, but some of the seas are connected.In addition to the "sea", there are five similar "lakes"——Dream Lake、Dead Lake、Summer Lake、Autumn Lake、Spring LakeHowever, some lakes are larger than the sea. For example, Menghu Lake covers an area of 70000 square kilometers, more thanSteam seaIt's much longer to wait.The part of the moon sea stretching to the land is called "bay" and "marsh", which are distributed on the front.There are five bays:Dew Bay, ShuwanCentral Bay、Hongwan、Meiyue Bay；There are three marshes:Sapropel、Pestilence bog、MengnumaIn fact, marsh is no different from bay.
Moon
The terrain of the moon sea is generally low, similar to the basin on the earth. The moon sea is 1 to 2 kilometers lower than the average level of the moon, and some of the lowest sea, such asRainy SeaThe southeastern part of is even 6000 meters lower than the surrounding area.LunarAlbedo(A physical quantity that measures the ability to reflect sunlight) is also relatively low, so it looks darker.
The area on the lunar surface higher than the lunar sea is calledLunaIt is generally 2~3 kilometers higher than the monthly sea level. Because of its high albedo, it looks bright.On the front side of the moon, the area of the lunar land is roughly equal to that of the lunar sea, but on the back side of the moon, the area of the lunar land is much larger than that of the lunar sea.It is known from isotope measurement that the moon land is much older than the moon sea, and it is the oldest topographic feature on the moon.
On the moon, in addition to the numerous impact craters intersected by canine teeth, there are also some mountains similar to those on the earth.Mountains on the moon are often named after mountains on the earth, such as the Alps,Caucasus MountainsWait, the longest mountain isApennine MountainsIt stretches for 1000 kilometers, but its height is no more than 3000 meters or 4000 meters higher than the monthly sea level.There are also some steep mountains and peaks in the mountains, whose height was overestimated in the past.Today, it is believed that the height of most mountain peaks is similar to the height of the earth's mountain peaks.Clementine in the United States in 1994Lunar probeIt was concluded that the highest point of the moon is 8000 meters“Chang'e-1”According to the data obtained, the highest peak on the moon is 9840 meters high.There are 6 mountains above 6000 meters on the lunar surface, 20 mountains between 5000 meters and 6000 meters, 80 mountains between 3000 meters and 6000 meters, and 200 mountains above 1000 meters.The mountains on the moon have a common feature: the slopes on both sides are asymmetric, and the slopes on the seaward side are very large, sometimes in the shape of cliffs, while the other side is quite gentle.This is because small bodies hit the lunar surface at a high speed. The powerful impact energy vaporizes, melts, breaks and sputters the rocks on the lunar surface, digging out a huge impact crater or impact basin. The huge impact energy of the impactor produces a series of faults and cracks at the bottom of the impact crater, inducing the eruption and overflow of basalt magma inside the moon, forming a dark lunar sea basin.Various sputtered materials ejected from the impact crater landed at different distances around the outer edge of the lunar sea, forming a gentle slope on the outer side of the moon.
In addition to mountains and groups of mountains, there are four cliffs hundreds of kilometers long on the moon surface.Three of them stand out in the sea of the moon, which is also called the "moon chasm".
Lunar radial striation
Another main feature of the lunar surface is that some relatively "young" craters often have beautiful "radiation patterns", which is a bright belt extending in all directions with the craters as radiation points, and it almost passes through the mountains, the moon sea and the craters in a straight direction.The length and brightness of radiation pattern are different, and the most striking one isTycho Ring MountainThe longest radiation pattern is 1800 kilometers long, which is especially spectacular at the full moon.Second, Copernicus andKeplerThe two ringed mountains also have beautiful radiation patterns.According to statistics, there are 50 craters with radiation patterns.
The reason for the formation of radiation lines has not been determined.In fact, it is closely related to the formation theory of circular hills.Many people are inclined to the theory of small body impact, believing that on the moon without atmosphere and with very small gravity, small body impact may make high-temperature fragments fly far away.Other scientists believe that the role of volcanoes cannot be ruled out, and the eruption of volcanoes may also generate radiation flying aroundshape。
Moon Valley
There are many famous rift valleys on the earth, such asEast African Rift Valley。There are also such structures on the moon surface -- those big black cracks that seem to be winding areMoon ValleySome of them stretch for hundreds to thousands of meters, and their widths range from thousands to tens of kilometers.The wider ones are mostly in the flat areas on the lunar land, while the narrower and smaller ones (sometimes called Yuexi) are everywhere.The most famous Moon Valley connects the Rainy Sea andCold SeaThe Great Alpine Moon Valley, which cuts off the Alps on the moon, is very spectacular.fromSpaceAccording to the photos taken, it is estimated to be 130 kilometers long and 10-12 kilometers wide.
Lunar image[8]
On October 5, 2014, scientists found a huge square structure hidden underground on the moon.This structure is 2500 kilometers wide. Scientists believe that it is an ancient rift system, which was later filled withMagma。[8]
Volcanic distribution
The surface of the moon is covered with huge layers of basalt (volcanic lava).Early astronomers believed that the dark areas on the surface of the moon are vast oceans, so they called them "mare", which means "sea" in Latin. Of course, this is wrong. These dark areas are actually plains composed of basalt.In addition to basalt structure, there are other volcanic features in the dark area of the moon.The most prominent, such as meandering lunar surface grooves, black sediments, volcanic dome andVolcanic cone。However, these features are not significant, only a small part of the volcanic traces on the moon surface.
Compared with the earth's volcanoes,Lunar volcanoIt can be said to be senile.Most lunar volcanoes are between 3 billion and 4 billion years old;Typical dark plain, 3.5 billion years old;The youngest lunar volcano is also 100 million years old.In the geological age, the earth's volcanoes belong to the youth period, and the general age is less than 100000 years.The oldestrock stratumOnly 3.9 billion years old, the oldest seabedbasaltOnly 2 million years.The young earth's volcanoes are still very active, while the moon has no signs of recent volcanic and geological activities. Therefore, astronomers call the moon an "extinct" planet.
Most of the earth's volcanoes are distributed in chains.For example, the Andes Mountains,Volcanic chainOutline alithosphereThe edge of the plate.The chain of mountains on the Hawaiian Island shows the hot spot of plate activity.There is no evidence of plate tectonics on the moon.Typical lunar volcanoes are located at the bottom of huge ancient impact craters.As a result, most of the moon's dark areas have a circular appearance.The edge of an impact basin is often surrounded by mountains and dark areas.
The shadow area of the moon is mainly on the front side of the moon.It covers almost 1/3 of this side.On the back of the moon, the dark area only accounts for 2%.However, the terrain on the back of the moon is relatively higher and the moon shell is thicker.It can be seen that controlLunar volcanismThe main factors are the terrain height and the thickness of the moon shell.
Geological map of the moon
In June 2022, the world's first 1:2.5 million lunar full month geological map will be released.It is understood that this geological map was developed by a team of Chinese scientists. Based on the data of China's Chang'e project, it makes full use of other international lunar exploration data and research results. Its elements mainly include 12341 impact craters, 81 impact basins, 17 rock types, 14 types of structures, etc.The lunar geological map system expresses comprehensive geological information on the surface of the lunar crust in terms of stratum, structure, lithology and chronology, and reflects the evolution process of lunar magmatism, impact events, volcanic activity, etc.[16]
On April 21, 2024, the world's first high-precision lunar geological atlas, including Chinese and English versions, will be compiled based on the scientific exploration data of the China Lunar Exploration Project (Chang'e Project)《1: 2.5 million lunar geological atlas》And《1: 2.5 million geological atlas of the moon》Officially released。Among them, the 1:2.5 million Lunar Full Moon Geological Atlas includes《1: 2.5 million full moon geological map》《1: 2.5 million lunar rock types distribution map》And《1: Outline map of 2.5 million lunar structures》The 1:2500000 geological atlas contains 30 standard geological maps of the moon.[33]The atlas has been integrated into the digital lunar cloud platform built by Chinese scientists, and serves for lunar scientific research, popular science education, landing area selection, lunar resource exploration and path planning of China's future lunar exploration projects.[34]
On May 16, 2019,National Astronomical Observatory, Chinese Academy of SciencesIt was announced that the research team led by researcher Li Chunlai of the station used the Chang'e-4 exploration data to prove that there were deep materials mainly olivine and low calcium pyroxene in the Antarctic Aitken basin on the back of the moon.The international academic journal Nature published this important discovery online.This discovery provides direct evidence for answering the questions about the composition of the lunar mantle material that have puzzled scholars at home and abroad for a long time, and will provide support for improving the model of the formation and evolution of the moon.According to the news from the National Astronomical Observatory of the Chinese Academy of Sciences,Chang'e-4 probeIt was the first time in human history that the soft landing on the back of the moon was detected in place. The research results based on the detection data successfully revealed the material composition of the back of the moon, confirmed the correctness of the inference that the moon mantle is rich in olivine, and deepened human understanding of the formation and evolution of the moon.
At noon on October 26, 2020 local time, NASAStratospheric Observatory for Infrared Astronomy SOFIA confirmed for the first time that there is water on the sunward side of the moon.This discovery suggests that water may be spread all over the moon's surface, not just in the form of ice in cold, dark areas.
During the observation mission, Sophia“Cravius crater”The water molecule (HtwoO）。Cravis Crater is one of the largest craters on the moon. It is located in the southern hemisphere of the moon and can be seen with the naked eye on the earth.The observation data shows that there is water with a concentration of 0.001%~0.004% in the ring mountain area, which is roughly equivalent to a bottle of 355ml bottled water in the surface soil of the ring mountain per cubic meter.This research result was published in the latest academic journal Natural Astronomy.
On October 8, 2021, the research paper "Age and composition of Chang'e-5 young basalt" was published online in the international academic journal Science.This is the first academic achievement published based on Chang'e-5 lunar samples.It proves that magma activity still existed on the moon 1.96 billion years ago, which provides key scientific evidence for improving the evolution history of the moon.[10]On October 9, 2021, the 1:2500000 Lunar Geological Series Map (hereinafter referred to as the Lunar Geological Series Map) passed the expert review.The lunar geological map series has two versions in Chinese and English, including a full moon geological map, 30 geological maps, as well as a lunar tectonic outline map and rock type distribution map.[11]
On October 19, 2021, the Chinese Academy of Sciences held a conference on the research results of Chang'e-5 lunar samples.The Chinese Academy of Sciences, jointly with several institutions, released to the world, and Chinese scientists revealed the mystery of the late evolution of the moon - the moon still has magmatic activity about 2 billion years ago. It is not only more "long-lived" than people think, but also the secret of "longevity" is different from what the scientific community had previously imagined, neither because the source region is rich in radioactive heat generating elements,It is not because the magma source area is rich in water that the melting point is reduced.Chinese scientists found from lunar samples collected by Chang'e-5 that the magma activity of the moon had lasted until about 2 billion years ago, and the life of the moon was about 800 million years longer than previously estimated.[12-13]Through the study of lunar samples, it is determined that the formation time of young basalt is 2.03 billion years, 800 million years longer than the previous human cognitionyear[27]。
The scientific research team of the National Space Science Center of the Chinese Academy of Sciences, based on the image and spectral data with ultra-high spatial resolution obtained by the "Chang'e-4" rover, identified the carbon chondrite impactor residues within 1 million years in situ on the lunar surface for the first time.Research shows that there is a possibility of impactor residues in relatively young lunar surface materials (such as the returned samples of Chang'e-5).The direct analysis of these impactor residues that may exist in the Chang'e-5 sample will provide an important reference for the evolution history of the composition and type of the impactor in the Earth Moon system, and is expected to further constrain the evolution of the orbital dynamics of the solar system and enhance the understanding of the impact history of the inner solar system.Relevant research results were recently published in the international academic journal Nature Astronomy.[14]
In August 2022, an international research team led by Zurich University of Technology in Switzerland observed the permanent shadow area on the moon using artificial intelligence algorithms.This AI is expected to "illuminate" permanent shadow areas, especially those areas that cannot be reached by natural sunlight despite rotation.This achievement was published in Geophysical Research Letters.The team has investigated more than six potential landing sites for the Artemis program.[17]
In September 2022, the scientific research team of the Institute of Geochemistry of the Chinese Academy of Sciences carried out a study on Chang'e-5 lunar soil samples. Through infrared spectroscopy and nano ion probe analysis, it was found that there was a large amount of solar wind generated water in the mineral surface of Chang'e-5, and it was estimated that the solar wind proton injection contributed at least 170 ppm to the water content of Chang'e-5 lunar soil.This study confirmed that the minerals on the moon surface are an important "reservoir" of water, providing an important reference for the distribution of water in the mid latitude area of the moon surface.This achievement was published in the international academic journal Nature Communication.[18]
October 2022On the 22nd, the latest research results of Chang'e-5 lunar soil samples were published online by Progress in Science.Chinese researchers have proposed a new lunar thermal evolution model.[19]
2022On October 31, Shandong University took the lead in completing the world's first 1:2.5 million lunar rock type distribution mappublish[20]。
In January 2023, the National Space Administration announced the scientific research achievements of Chang'e-5 lunar samples:Lunar regolithThe sample has been accurately measured and its age is 2.03 billion years, which indicates that China has foundThe youngest volcanic activity time on the moon so far.Previously, the scientific community believed that the youngest volcanic activity on the moon was about 3 billion years agoApollo 6The moon soil brought back was studied.[21-22]
In March 2023, Chinese and British scholars measured the water in the impact glass beads in Chang'e-5 lunar samples, and the average water content could be as high as 0.05%.It is revealed that the impact glass beads in the lunar soil are a water storage treasure house, and they can maintain the lunar surface water cycle.[23]
May 2023In April, scientists uncovered the mystery of the internal structure of the moon, indicating that it has a fluid outer core and a solid core similar to the Earth。Its core is probably made of iron.[24]
On September 1, 2023, the National Aeronautics and Space Administration (NASA) announced on its official website that its "Lunar Reconnaissance Orbiter" (LRO) had photographed a new "meteorite crater" on the surface of the moon, which was presumably caused by the impact of the Russian "Lung-25" probe.[26]
October 2023Hu Hao, chief designer of Chang'e 5 mission, said that Chang'e 6 missionThe landing area is the South Pole Aitken Basin on the back of the moon.[28]
On October 26, 2023, a new research released by an international team showed that after analyzing the lunar samples collected by the Apollo 17 mission, researchers found that the moon was at least 4.46 billion years old, which was more than scientists had previously thought40 million years older.[29]
In December 2023, the Chinese 32nd Antarctic Expedition team found a lunar meteorite (GRV150357) in Grove Mountain, Antarctica.The preliminary study shows that this is a complex mineral clastic breccia, composed of different rock fragments from the lunar highland and the lunar sea. It is an ideal object to understand the complex lithology of the lunar crust, and also an important supplementary object for China to carry out research on lunar samples.[30]
After dark on February 15, 2024 (Beijing time), people can see the astronomical landscape accompanied by the moon and Jupiter with the naked eye in the southwest sky, that is, the Jupiter moon associated celestial phenomenon.At that time, Jupiter will be at the lower left of the moon, and its brightness will reach - 2.3.[32]
