What are Some Major Landmarks on the Moon?

A lunar crater is a circular crater formed by the impact of a meteorite on the surface of a planet, satellite, asteroid or other celestial body. As the size of the meteorite particles hits the surface of the moon, different crater widths of different sizes will be hit, but the interesting thing is that these pits are quite shallow.

Lunar crater

A lunar crater is a circular crater formed by the impact of a meteorite on the surface of a planet, satellite, asteroid or other celestial body. As the size of the meteorite particles hits the surface of the moon, different crater widths of different sizes will be hit, but the interesting thing is that these pits are quite shallow.

Chinese name

Lunar crater

Foreign name

Moon craters

Alias

Crater

Location

Moon

Cause of formation

Bump

Shape

Pit

The main signs of the crater are:

Craters are generally circular structures

At present, the detection results of dozens of craters on the surface show that they are mostly circular structures. Older pits are also oval or waist-shaped due to the influence of tectonic movement.

Crater rim

Most craters have better lip lip, that is, the edge of the crater. It is formed by the accumulation of projectiles along the edges of the pit. Some craters are eroded because of their old age, and sometimes the crater itself is also eroded, so it is not easy to identify. However, the residual strong deformation and the cracked rock are still a circular area. .

Complex structure at the bottom of the pit

After the rocks at the bottom of the crater are bombarded by huge meteorites, a certain degree of rebound occurs due to stress release. Therefore, the central bulge often occurs at the bottom of some large craters; due to the damage to the rocks at the bottom of the pit, the artificial seismic wave is reflected Extremely irregular; gravimetric measurements show that the crater is a negative gravity anomaly and the volcanic eruption is a positive anomaly. In addition, the bombardment of a huge meteorite may trigger or control the intrusion of deep magma, as famous in Canada

As the size of the meteorite particles hits the surface of the moon, different sizes of impact

Although humans have landed on the moon, a neighbor of the earth long ago, and rely on timely grasp of many facts about the moon, there are still many mysteries of the moon to be revealed. At the recent European Planetary Science Conference (EPSC), scientists pointed out that many craters on the moon can well hold samples of life from Earth, and there may be unknown

December 18, 2009 According to the BBC, NASA uses lunar surveys

French scientists have recently discovered in Egypt what is said to be the largest crater area in the world. This area covers an area of 5,000 square kilometers.

The French National Research Center pointed out in an internal journal in October that scientists from the center cooperated with the University of Cairo in Egypt to find a crater area composed of hundreds of craters in a region called Gilf Kabil in the Libyan desert in southwestern Egypt . These craters vary in size, ranging from 20 meters to 1 kilometer in diameter, with the deepest craters reaching 80 meters.

A team of French and Egyptian scientists used satellite photos to find the world's largest crater area in Egypt. The crater area is located on the border between Egypt and Libya, where scientists found traces of more than 100 meteorite falls.

French team leader Philip Payou said that in order to spread to an area of 5,000 square kilometers, several meteorites must fly to this area, and they had already become multiple fragments due to air friction when they entered the earth's atmosphere. Piece. According to preliminary judgment, these craters appeared 50 million years ago.

Experts are currently analyzing the meteorite fragments in the crater to prove that many meteorites have fallen together in this area about 50 million years ago.

Meteor Crater, Chicxulub, Mexico

Manicouagan Crater, Canada

Kara-kul, Tajikistan

Clearwater Lakes, Canada

Mistastin Lake, Canada

Gosses Bluff, Australia

Aorounga Crater on Lake Chad

Deepwater Bay, Canada

Bosumtwi, Ghana

Barringer Crater, Arizona, USA

Meteorites are generally considered to be fragments generated by asteroids, planets, and large satellites colliding and breaking with each other during operation. They diffuse into the universe in the form of interstellar dust. If they are captured by the gravity of the earth and sucked toward the earth, they will form a meteorite. When they entered the dense atmosphere of the earth at a fast speed, most meteorite rubbed with the atmosphere, generated heat, glowed and vaporized, but some remained and fell to the surface. This is the meteorite we found on the surface. According to the different chemical composition of the meteorite itself, it is roughly divided into three types: iron meteorite, also called

The crater formed by a huge meteorite hitting the earth more than two billion years ago won the title of "World Natural Heritage" on the 14th, and the South Africa where the crater is located also owns the seventh World Heritage Site.

After three years of efforts, mainland scientists have confirmed that the Liaoning Xiuyan crater is a meteorite impact crater and the first crater to be discovered and confirmed in China. Interestingly, there are currently 64 households living in the pit. Villagers rarely get sick, and it is a well-known longevity village.

After three years of hard work, such as Chen Ming and others from the Guangzhou Institute of Geochemistry, the Chinese Academy of Sciences, he finally found a series of evidence that the strong impact of a meteorite caused the rock to deform, fragment, and locally melt, and the rocks and minerals were impacted by metamorphism. Chen Ming and others recently published their research results in the "Chinese Science Bulletin", which officially confirmed that the Liaoning Xiuyan pit is a meteorite

The "Meteor" crater, located in Arizona, USA, has become the first to be identified as a trace left by a huge meteorite impact. The crater is 1,250 meters in diameter and about 175 meters deep.

According to information released by scientists, a crater was formed as early as 50,000 years ago due to the fall of an iron meteorite. The first report on this crater was submitted to the American Academy of Sciences in 1909. It can be said that "

Find the basis for the hypothesis of meteorite bombardment in the formation of circular craters and craters on the surface of the Earth's moon, Mercury, Mars and its satellites, and determine the existence time and distribution of craters. At the same time, it provides valuable data for studying the impact of huge meteorite on the formation of the earth and other planets, the influence of primordial heat and the rotation of the rotation axis, as well as for studying magmatic activities, sudden events and planetary evolution.

The study of shock metamorphism of minerals and rocks will further enrich the content of petrology, mineralogy, crystallography, and high-temperature and high-pressure geology, and provide a reference for understanding the mantle material properties and physical and chemical characteristics, that is, for the study of deep earth. The temperature and pressure history of the rock when it is bombarded can also be estimated from the characteristics of the impact effect, which has certain practical significance for understanding the power of ground and underground nuclear tests and artificial blasting, the radius of damage, and engineering protection and the synthesis of minerals such as diamond.

Because huge meteorite bombardment can cause underground magma to rise, invade, and mineralize, a new diagenesis and mineralization theory has emerged that links external action with deep earth action.

Study the distribution morphology and taper of the crater on the surface, especially the metamorphic effect after the bombardment. It can directly infer the direction, speed, mass, and ablation of the meteorite when it descends, and provide a basis for the soft landing of the spacecraft.

According to the BBC, NASA uses the "Diviner" instrument on the Lunar Reconnaissance Orbiter (LRO) to detect the interior of the crater that is always in the shadow on the moon. The coldest place in the solar system was found in a crater in the Arctic region of the moon, where the lowest temperature can reach minus 249 degrees Celsius.


"This has led to dramatic changes in the length and temperature of the polar regions," Pejer said. The "Fortuneteller" observed the lowest summer temperature in Antarctica's darkest crater is about 35 absolute temperature scales (minus 238 degrees Celsius); but " The results of the "Fortuneteller" observations show that the temperature of the southwestern edge of the bottom of the "Hermite Crater" in the northern hemisphere is only about 26 absolute temperature scales near the winter solstice.
The temperatures on the southern sides of the craters of the "Peary" and "Bosch" craters have reached almost this temperature. The analysis pointed out that to find such a cold place on the surface of another celestial body, it is necessary to go outside the "Kuiper Belt", that is, outside Neptune's orbit.
"To bring the temperature down to this low, all other possible sources of heat must be removed. The craters of the moon's polar regions cannot get direct sunlight, and the coldest places can't even get indirect sunlight. Maybe only the distant cliffs produce Some of the radiation can reach these areas, and they can quickly get cold. So these places reach such low constant temperatures. "
This finding strongly supports the idea that perhaps some craters on the moon have long had water ice and some more volatile substances that require even colder storage temperatures. ^[3]

The discovery, published in the journal Nature-Earth Science, questions our long-standing beliefs about the Moon's material composition. The academic view has long been that small celestial bodies will be completely evaporated when they collide with larger celestial bodies. Some unusual minerals, such as spinel and olivine, have been found inside many lunar craters, but these minerals are very rare on the surface of the moon, so it is believed that these minerals should be the moon surface exposed by the impact of small celestial bodies Substance composition.

However, spinel and olivine mineral components are very common in asteroids and meteorites. Prior to this, scientists have been in some large lunar craters, such as Copernicus, Geophys and Tycho Crater, and so on. The diameter of these craters is about 100 kilometers, and the spinel and olivine mineral components have been found in the crater bottom and the area near the central peak.