There are precedents in history. 65 million years ago, an asteroid with a diameter of 10 km hit the earth's surface at high speed, which eventually led to the complete extinction of dinosaurs that ruled the earth for 65438+600 million years. Scientists simulated the impact in Conan the Destroyer. If it happens in modern times, human civilization will be helpless and can only watch.
Although the energy directly generated by celestial impact was not enough to make dinosaurs extinct, the ability generated by celestial impact led to volcanic eruption and forest burning. Finally, thick smoke and dust entered the atmosphere to block the sun, and the earth entered a dark period for decades.
No light means that plants can't carry out photosynthesis, and eventually the earth's ecosystem suffers great damage, and most species, including dinosaurs, become extinct.
In addition, a celestial impact event that is very close to us in time is the Tunguska Big Bang that happened on1June 30th, 908. The explosion occurred near the ground in the Tunguska River area of Russia, resulting in the destruction of more than 2,000 square kilometers of forest areas. The energy released by the explosion was equivalent to 1000 atomic bombs exploding in Hiroshima. Later, scientists simulated that an asteroid with a diameter of 30-50 meters entered the atmosphere and disintegrated and exploded when it approached the ground under high-speed friction.
Of course, there have been many speculations about the Tunguska Big Bang, such as the annihilation of positive and negative particles, the crash of small black holes or flying saucers and so on. But scientists finally determined that it was an asteroid impact.
The celestial bodies in the solar system all run in a stable system, and each celestial body has its own specific orbit, which does not interfere with each other's safety. However, for some small celestial bodies, they are easily disturbed by the gravity of other large celestial bodies, which leads to changes in their orbits and may eventually hit the earth.
The influence of celestial bodies on the earth is not very rare. Scientists have finally worked out rough data through geological research. In the life history of 3.8 billion years on earth, they may have experienced 22 extinction events of different degrees. We are all familiar with those five mass extinctions. At least 1 1 of these extinction events is related to the impact of celestial bodies. Because all living things can't cope with such a disaster, it is difficult for even modern humans to actually operate. However, their potential threat does always exist, so many countries' space systems have monitoring institutions for near-earth objects to play an early warning role.
Facing the threat of extraterrestrial bodies, human beings have conceived many ways to deal with it, but they have never really implemented it. This time, NASA will really verify the technology of preventing asteroid impact, mainly by changing the orbit of asteroids through effective means.
Scientists chose the asteroid Dimorphos as the target, which is the smaller one in a dual asteroid system, with a width of160m and a distance of 1 1 10,000km. It revolves around the asteroid Didymus. NASA plans to launch the Double Asteroid Redirect Test (DART) mission in July, 20021. According to the plan, it will hit the asteroid Dimorphos in September 2022. The purpose of this impact is to change the orbit of the asteroid Dimorphos around Didimos.
At the same time, scientists will track the impact results through telescopes on the ground. At the same time, ESA will launch a "Hera" probe to the asteroid Dimorphos in 2024, with the purpose of field observation to confirm whether the orbit has changed and whether it is running along a new orbit.
In the future, if this technology is successful, it can be used to deal with the impact of asteroids on the earth, which also makes life on earth safer.