About Apophis in 2029

The Apophis asteroid was discovered in 2004. It is more than two football fields wide and 390 meters wide. Because it is possible to hit the earth in the relatively near future, it has attracted much attention from scientists in recent years. Scientists once thought that if Apophis hit the earth, it would not lead to global destruction, but it might cause serious regional disasters. Impact disaster

Scientists held an expert meeting on "Near-Earth Objects" in London, England, to discuss the method of "saving the earth at the end of the day". Monica Grady, a meteorite expert from the Open University of the United Kingdom, said: "It is only a matter of time before a near-earth asteroid collides with the earth, not whether it will happen. Many smaller space objects melted when they rushed into the earth's atmosphere, so they failed to collide with the earth. Asteroids with a diameter greater than 1 km will collide with the earth every few hundred thousand years, and asteroids with a diameter greater than 6 km will collide with the earth every few hundred million years. Such an impact will lead to extinction. This time, human beings are faced with a big guy who is late. " Apophis was previously thought to have a 2.7% chance of hitting the earth in 2029. After checking the orbit, NASA scientists found that Apophis will pass by the earth in 2029, but will return to the earth in 2036, and may break through the atmosphere and collide with the earth!

It is reported that "Apophis" has been included in the fourth level of "Turin level", and the level of 10 means an inevitable global devastating collision. Apophis is the most dangerous asteroid ever discovered. Previous calculations show that the probability of it colliding with the earth in 2036 is as high as one in 370 thousand! Allen fitzsimmons, an astronomer at Queen's University in Belfast, UK, said that when it passes near the Earth on April 13, 2029, the earth's gravity will change its orbit, and it will visit the Earth again in 2036 and may collide with the Earth. Hawking, a famous British theoretical physicist and mathematician, pointed out that due to the threat of near-earth small objects, human beings must emigrate to other planets suitable for survival in order to get rid of the fate of extinction. At present, the near-earth asteroid that poses the greatest threat to the earth is the Apophis asteroid, which will "pass by" the earth in 2029; If the Apophis asteroid passes through the gravitational eye above the Earth with a probability of one in 370,000 (gravity is only one quarter of the normal value), it will be dragged into the orbit around the Earth, and in 2036, seven years later, it will enter the atmosphere from the North Pole, pass through the Siberian Plain, pass through big cities such as new york, and circle the Earth, and eventually fall into a place in North Africa, which is the highest risk level among small celestial bodies discovered so far.

Since 1990s, scientists have held various relevant international academic seminars every year to discuss countermeasures. At present, NASA, the European Space Agency and some related agencies are strengthening the monitoring and tracking of small celestial bodies that are most likely to endanger the earth. Space "clairvoyance"-Hubble telescope is also constantly monitoring their "activities". American researchers pointed out that it is extremely unlikely that an asteroid will hit the earth at that time.

Donald yeomans, head of the Near-Earth Object Project Office of NASA, told the media that from the perspective of natural probability, the probability that an Apophis asteroid will hit the Earth in 2036 is only one in 250,000. The reason why this probability is so small is that if the asteroid Apophis wants to enter the orbit of colliding with the earth, it must pass through the "gravitational keyhole" area of near-earth space, and then it may collide with the earth under the action of the gravity of the earth. However, the diameter of this asteroid is more than 300 meters, which is much smaller than that of the "gravitational keyhole". It is extremely unlikely that the high-speed flying "Apophis" asteroid will fall into the "gravitational keyhole".

Yeomans also pointed out that with the science and technology mastered by human beings, experts will not wait until 2036 when asteroids threaten the earth before taking countermeasures.

Yeomans said that the more realistic prospect is that when the Apophis asteroid flies through the Earth from 20 12 to 20 13, astronomers will make a detailed analysis of its orbit with various space telescopes and ground observation facilities, and then experts can draw a conclusion whether the asteroid may collide with the Earth. If there is a high possibility of collision, NASA can also push the asteroid out of the orbit that collides with the earth. A simpler way is to launch a spaceship and crash an asteroid into an orbit far away from the earth.

On July 4th, 2004, the American Deep Impact Detector successfully bombarded the Temple 1 comet with an impactor. Yeomans believes that this bombardment test is a very useful attempt to prevent asteroids from threatening the earth. In order to cope with the worst disaster, scientists have put forward many theoretical methods to change the orbit of asteroids that hit the ground. The "Advanced Concept Group" of the European Space Agency has designed a method to push asteroids out of collision orbit with a row of satellites or rockets. The most interesting and simplest way for scientists is to send a spaceship to collide violently with an asteroid, thus changing its direction. In order to deal with the threat of Apophis, the European Space Agency is going to launch the Don Quixote project and send two spacecraft to an experimental asteroid. One of the spacecraft named Sidargo will collide with this asteroid at high speed, while another spacecraft named Sankoh will measure the orbital changes of nearby asteroids. There is also a proposal to bomb asteroids with nuclear bombs.

However, the latest observations may ease people's panic about Apophis. The University of Hawaii uses the latest observation data obtained by the astronomical telescope deployed near the top of Mauna Kea (the extinct volcano on the island of Hawaii, the highest mountain in the Pacific Ocean, with a height of 4,205 meters) to enable scientists to recalculate the trajectory of this space boulder. Fortunately, the new trajectory shows that it is almost impossible for this asteroid to hit the earth. The time when the asteroid hit the earth was locked at 207 1. A huge space star crashed into the earth with a dazzling flame, causing shocking waves and instantly engulfing coastal cities ... This is a tragic scene in the American blockbuster "Collision between Heaven and Earth". This unfortunate experience may really happen in the world. A few days ago, astronomers announced the discovery of the most dangerous near-earth asteroid, which partially overlapped with the Earth at 207 1. The probability of two stars colliding is one in a thousand.

207 1 year collision?

1, the asteroid is busy with experts.

Asteroid experts may be the researchers who attract the most media attention this year. They issued warnings of "big collision between heaven and earth" again and again, causing anxiety and panic of the world again and again. In September 2000, astronomers at Cornell University in the United States suddenly announced that an asteroid code-named 2000QW7 "brushed" the earth a week ago, and scientists didn't notice it until five days after it flew to the earth. After a false alarm, scientists came to a gratifying conclusion: if this asteroid hit the earth, it could destroy 654.38+05 billion people!

A wave of unrest, another wave. Its impact energy is equivalent to 100 Hiroshima atomic bomb, which caused public outcry for a time. But just one day later, astronomers urgently corrected their previous judgment and thought that the possibility of "meeting" with the earth was about one in a thousand, and it was in the more distant year of 207 1 year.

Nevertheless, the discussion about the impact of asteroids on the earth is not over, and more and more people are beginning to pay attention to the possibility of "a big collision between heaven and earth". British scientists even formally submitted a report to the government, suggesting that the government must actively take preventive measures. China Purple Mountain Observatory also decided to invest 20 million yuan to build the largest asteroid telescope station in China.

The reporter was confirmed by Beijing Observatory of Chinese Academy of Sciences that this asteroid is indeed the most dangerous asteroid discovered by human beings so far. Its orbit is very similar to that of the earth, with a time of 354 days around the sun (the earth cycle is 365 days). Zhu Jin, the only asteroid observation researcher at the Chinese Academy of Sciences, told reporters that this dangerous asteroid will not "collide head-on" with the Earth because its turn is consistent with the Earth. The latest observation shows that its orbit will "coincide" with the earth's orbit at 207 1, but it is hard to say whether the two stars will meet.

With further exploration, perhaps this terrible conclusion will be ruled out.

According to researcher Zhu Jin, at present, the international astronomical community does not know much about this asteroid. Astronomers judge that its diameter is about 30 to 70 meters only from its brightness. The premise of this judgment is that it must be an ordinary asteroid. But if it is a metal object, the volume is much smaller. Observers still "can't see" its material structure. It may be a stone, or it may be a propeller fragment of a human spaceship in the 1970s.

2. The ancient earth is full of scars.

Asteroids are celestial bodies that orbit the sun like the earth, but they are too small to be called planets. The largest asteroid discovered at present is only about 1000 km in diameter. Asteroids are only the size of pebbles. According to Zhu Jin, an asteroid observation researcher at the Beijing Observatory of the Chinese Academy of Sciences, there are 1 106 near-earth asteroids discovered by humans (as of September 18, 2000), of which 16 are more than 240 kilometers in diameter, all of which are located in the space from the inside of the Earth orbit to the outside of Saturn's orbit.

People's fear of asteroids is not without reason. Because a smaller asteroid hitting the earth will also bring disaster. It is reported that 1908, an asteroid with a diameter of about 50 meters exploded over the tunguska region of Siberia, destroying about 2,000 square kilometers of forest, and the dust floating in the air was as high as 10,000 meters. This explosion is called the Tunguska Big Bang. (But this news has not been confirmed, and it is still a mystery. ) 65 million years ago, the impact of an asteroid with a diameter of about one kilometer destroyed many kinds of life on the earth, including dinosaurs. Experts point out that in the four billion years since the birth of the earth, dangerous "whispers" have left many scars on the earth. There are more than one hundred celestial impact craters discovered by human beings. The largest and oldest is Foley Pit in South Africa, with a diameter of 140 km and a history of19.7 million years. Scientists have analyzed that this is a meteorite or asteroid with a diameter of 10000 meters, and its impact force is equivalent to 1000 billion tons of atomic bombs.

However, astronomers also pointed out that because each asteroid has its own orbit, cosmic "traffic accidents" like cross collisions are not common. According to experts' analysis, the probability of an asteroid with a diameter of more than two kilometers hitting the earth only happens once every 500,000 years. The impact of an asteroid with a diameter exceeding 100 meters only occurs once every 10,000 years.

3. Two major vulnerabilities in the monitoring network

A large number of human monitoring of dangerous asteroids began in recent years. 1994, comet Sumer-Levy 9 collided with Jupiter, which was called the biggest space traffic accident in the 20th century. Since then, the United Nations has held three meetings to prevent asteroids and comets. Since 1995, there has been an upsurge of asteroid exploration in astronomy. Zhu Jin, a researcher at the Beijing Observatory of Chinese Academy of Sciences, told reporters that there are six major asteroid monitoring programs in the world, including the Schmidt program in China. But the most effective is the spacewatch program (space monitoring program) in the United States. This plan starts from 1985. Newton reflecting telescope, located in Kit Peak, Arizona, is used to search for and discover near-earth objects. This is the largest asteroid observation program in the world at present, and two or three near-earth asteroids can be found every two months on average. The "Schmidt CCD Asteroid Project" of Beijing Astronomical Observatory of Chinese Academy of Sciences started from 1995, using the Schmidt telescope of Hebei Xinglong Observation Base. More than 2000 asteroids have been discovered, including 5 near-earth asteroids. During the periods of 1997 and 1998, the achievements of Beijing Observatory were still in the top five in the world, but later, due to the increase of investment from various countries, more and more institutions surpassed Beijing Observatory.

SpaceguardFoudation is considered as the most successful international cooperation monitoring program at present. The organization was established in Rome on 1996, and is composed of well-known experts in the field of near-earth asteroids. Its purpose is to protect the earth's environment and prevent the impact of comets and asteroids.

Neat "near-Earth asteroid tracking" plan. In cooperation with NASA and the US Air Force, the 1 m telescope of the ground electro-optical deep space monitoring station of the US Air Force in Hawaii was used. In addition to these observation plans, there are also observation plans related to the US military, such as LINEAR and LONEOS. However, due to the fragmented monitoring plan and uneven telescope layout, there are still many "dead corners", so there is an amazing situation that the 2000QW7 asteroid was discovered after "scraping" the ground.

Zhu Jin believes that there are two major loopholes in the near-earth asteroid monitoring network: one is the inequality between the north and the south. The stations of the above major monitoring plans are all located in the northern hemisphere, while the number of telescopes in the southern hemisphere is quite limited. Therefore, it is impossible for people to monitor dangerous asteroids in the entire airspace. Second, there is a "dead angle". The biggest "dead angle" is the area where the sun shines. When an asteroid flies from the direction of the sun, it can't be seen by the ground telescope because of "backlight". It is necessary to set up a space observation telescope in the orbit between the sun and the earth to avoid the interference of sunlight. This plan has been put forward for a long time, and it is unlikely to be realized. Although scientists have realized the importance of establishing a more rigorous monitoring system, it takes too much money to cast this important life insurance for human beings, and people can only wait patiently.

4. A big collision with global defense

Experts believe that once an asteroid is found to have the possibility of hitting the earth, human beings need to have enough time to prepare for defense, and the preparation time is generally more than ten years. It is difficult to take measures when the stars in the universe are very close to the earth, just like in the American blockbuster "Collision of Heaven and Earth". So the longer the warning time, the better.

Generally speaking, the flight speed of asteroids may exceed the speed of existing human aircraft. When it doesn't hit head-on but approaches in the same direction, the aircraft launched by human beings can't catch up with it in a short time. Therefore, humans can only find them early, launch the aircraft into outer space to "wait" and then try to push it out of orbit. The farther this "battlefield" is from the earth, the safer mankind will be. So monitoring is the first priority.

Zhu Jin believes that human beings have very limited means to change the orbit of asteroids. Since mankind has not yet mastered the ability to launch weapons directly into outer space, the only way that mankind can think of is to intercept asteroids in outer space with a space shuttle loaded with nuclear bombs and smash them or make them deviate from orbit with nuclear missiles. But this method may not be effective. Because for some stars with loose structures, the effect of explosion is very limited. When the asteroid is far away, people can't observe its material properties.

The most dangerous asteroid just discovered, 2000SG344, is still unknown, but judging from its reflectivity, its diameter is about 30 to 70 meters. Therefore, it takes a long time from discovery to tracing, to analyzing physical properties, and then to choosing preventive measures. But what is more worrying is that other more dangerous long-period comets are more difficult to observe. Once people find that they will collide with the earth, they usually only have four months to prepare. And this preparation process is really like racing against a meteor.

Fortunately, asteroids around the world have realized the importance of full airspace monitoring, and a more thorough monitoring system is being planned. It is reported that the CatalinaSkySurvey monitoring plan of the United States plans to arrange a number of large telescopes in the southern hemisphere to supplement the still-defective human space defense network.

A wave of unrest, a wave of rise again? 2 140 nightmare?

The website of NASA announced that American astronomers had discovered an asteroid numbered S-20090820maxB and named Apophis-2 by scholars.

This asteroid is located in Orion B and is flying to the Earth at a speed of 50,000 kilometers per second.

Such asteroids are collectively referred to as near-earth asteroids. The study of these asteroids has been deepened, because they may collide with the earth at least in theory. Relatively successful projects include Lincoln's Near-Earth Asteroid Research Program (LINEAR), Near-Earth Asteroid Tracking Program (NEAT) and Lovel Observatory's Near-Earth Object Search Program (LONEOS).

Scientists predict that if this asteroid flies to the earth at this speed, it will reach the earth between 2 140 and 2 143, and the power brought by this asteroid is enough for the sum of 100,000 atomic bombs. Apophis has been one of the most interesting celestial bodies since it was discovered in 2004. Steve chesley, a near-earth object scientist at NASA's Jet Propulsion Research Institute, said that the latest calculation method and recent data show that the possibility of Apophis hitting the Earth on April 13, 2036 has dropped from one in 45,000 to about four in a million. Scientists still believe that this asteroid will be18,300 miles (about 29,450 kilometers) away from the earth's surface on April 3, 2029, thus creating the closest record to the earth. Of course, this record is harmless to the earth.

According to the latest data, the asteroid Apophis will approach the Earth again in 2068, with a one in three million chance of hitting the Earth. With the further collection of Apophis asteroid operation information, the possibility of impact will be ruled out. Accurate orbit calculation further shows that we can think that the asteroid Apophis will still attract the attention of the scientific community, but it should not cause any panic. Don yeomans, director of the Near-Earth Objects Research Office of NASA's Jet Propulsion Institute, said that the public can always pay attention to our research on Apophis asteroids and other near-earth objects.

According to the statement issued by NASA's Jet Propulsion Laboratory, when the asteroid Apophis 20 13 1.9 passed about14.5 million kilometers away from the Earth, the researchers carefully observed it through the deep space radar in Mojave Desert, California and Arecibo, Puerto Rico, and further judged its orbit. How to prevent near-earth small objects from hitting the earth? Professor Zhou Haizhong, a famous scholar in China, said in an interview with the media: At present, there are many defense schemes in the scientific community, some of which are ready to be put into action. The schemes with "theoretical feasibility" are:

One is to blow it up with nuclear weapons, but the trouble is that the explosion is likely to turn it into many small "killers" and throw radioactive objects into unpredictable orbits; For some near-earth small objects with loose structures, the effect of explosion is very limited. This method has been mixed.

The second is to hit it with a spaceship, change its orbit or smash it. This method is more effective, but like the use of nuclear weapons, it may also amplify the disaster several times.

The third is to use the aircraft to exert pressure on it (that is, to use mechanical force) to accelerate or decelerate it, thus changing its flight direction. This method is ideal, but it is not easy to realize and has certain risks.

Fourthly, it uses laser to make its surface substances diverge outward, thus generating reverse acceleration to change the flight direction; Or use super laser to destroy it into small pieces that are harmless to the earth. This method is also ideal, but it must have a super-power laser system.

Fifth, change its color with paint, affect its absorption of sunlight and heat, and change its orbit through the change of heat energy. This method is slow, and how to transport a large amount of paint is also a problem.

Sixth, send a huge kite-shaped solar sail to it with a rocket, and the open solar sail will gradually push it away from the original orbit by using the pressure generated by the rebound of solar photons. This method is technically demanding and difficult.

Seventh, insert a rocket-like device on its surface, so that this device can continuously spray substances and change the flight direction through reaction like a jet plane.

Apophis flew over the earth.

Scientists discovered this asteroid named after Apophis, the god of destruction in ancient Egypt, in 2004, with a diameter of about 300 meters. According to calculation, once it hits the earth, its power is equivalent to 500 million tons of TNT explosion, which will release 10 times more energy than the previous most powerful hydrogen bomb explosion. The pictures taken by the astronomical camera show that Apophis is 654.38+0.4 thousand kilometers away from the earth when flying over it, which is out of the orbit of the moon around the earth, so it will not pose a threat to the earth.

Previously, Fazikas, a spokesman for the Royal Canadian Astronomical Society, had speculated that Apophis would pass 30,000 kilometers away from the Earth in 2029, thus creating a record closest to the Earth, when the two sides might collide. However, after further research, some scientists found that the possibility of Apophis colliding with the earth in 2029 is very small, because Apophis will cross an area called "gravitational keyhole" and may deviate from the orbit because of the influence of the earth's gravity.

Russian astronomers predicted that an asteroid code-named Apophis would collide with the Earth on April 13, 2036, attracting global attention. Experts from Purple Mountain Observatory said in an interview yesterday that Apophis is the most dangerous near-earth asteroid discovered at present, and there will be several opportunities to "pass by" the Earth from 20 13 to 2039. But according to the observation results, it is unlikely to collide with the earth. Apophis intersects the earth's orbit.

Ji, a researcher at the Purple Mountain Observatory, told reporters that an asteroid refers to a celestial body in the solar system that orbits the sun like a planet, but its volume and mass are much smaller than that of a planet. Because they all revolve around the sun, the orbits of asteroids and the earth intersect. This asteroid named Apophis was first discovered by American astronomers in 2004. Its diameter is more than 270 meters, more than the size of two football fields.

Just because the tracks intersect, there is a fear of collision. According to the calculation, the explosive force of an asteroid is directly proportional to its size. Every time the diameter increases by 10 times, the explosive power increases by 1000 times. Generally, asteroids with a diameter of more than140m can pose a great threat to the earth, not to mention Apophis, which is bigger than two football fields. Once it hits the earth, it may be a huge disaster.

The "closest distance" appeared on April 13, 2029.

Ji said that it will take at least eight years to completely observe Apophis orbiting the sun. Scientists can only estimate its operation through observation and correct its orbit according to the continuous update of observation data.

According to calculation, Apophis will pass the earth for the first time in the next few decades from 2065438+20031October 9. It will be about 6.5438+0.5 million kilometers away from the earth. Next, if its orbit does not deviate, it will usher in its "closest distance in history" to the earth-35,000 kilometers on April 13, 2029.

"This is almost the height of geosynchronous satellites, and it is110 of the distance between the earth and the moon." Ji Jiang Hui said that such a short distance is very dangerous. If you deviate from the orbit under the influence of external forces, you are very likely to hit the earth.

In the history of astronomy, the probability of a major disaster caused by an impact is very low.

This time, Russian experts also noticed this "passing by" in 2029. They believe that when this time passes by, Apophis's orbit will deviate due to the gravity of the earth, and then it will hit the earth at the next moment of passing by, that is, in 2036.

"I don't think I will fight." Ji Jiang Hui told reporters that NASA has also analyzed that the probability of Apophis hitting the earth in 2036 is only one in 250,000. He also told reporters that in the history of astronomy, near-earth asteroids collided with the earth from time to time, but the probability of causing major disasters was very low. Moreover, with the more and more in-depth understanding of the asteroid's operation law in the astronomical community, in the near future, it is entirely possible for human beings to interfere with the asteroid's impact on the earth through scientific means, such as launching aircraft and changing the asteroid's orbit with lasers, which have all entered the experimental stage.