American spacecraft is about to hit the "innocent" asteroid: human beings test the planet defense for the first time on the spot

On September 26th, a spacecraft of an automatic vending machine -sized spacecraft at 11 million kilometers away from Earth will hit a "innocent" asteroid Dimorphos with a diameter of 160 meters per second. This upcoming "violence" operation is the first time that human beings have conducted field testing on the planet defense tasks in history, that is, NASA (NASA) dual -planet redirect redirectional test (DART).

The DART task team recently observed Didymos, a dual -asteroid system, and the target small planet Dimorphos is one of the small satellites. NASA hopes that this collision will push Dimorphos into a orbit closer to Didymos, which shorten its running cycle for nearly 12 hours. In the future, similar impacts can turn threatening asteroids. But the new simulation and laboratory experiments show that the success of this task depends on whether these small stars are a solid rock or loose gravel pile.

The answer will be revealed from the meteor -pit and spraying objects generated by the impact, which may determine the difficulty of hitting asteroids. Compared with the larger asteroids that caused large -scale extinction events before, the possibility of double asteroids hit the earth by thousands of times, and they have the ability to destroy a country, which makes these small celestial bodies become the top priority of planet defense work. The weight of the middle. But for the ground telescope, they are just a small light spot, which is difficult to detect, let alone research.

When a celestial body blocks another celestial body, their light becomes darker. By monitoring micro fluctuations from Dimorphos and Didymos light, scientists of NASA can understand their speed and other information. This will allow scientists to design an independent navigation system that guide the "dart" to approach "prey" with the help of the new solar ion pusher.

But no one will be sure of what will happen next. "Suppose it is a solid rock, we have a solid aerospace, which is essentially playing a large billiard game in space ... basically it can be solved as a simple physical equation." DART task observation team Cristina Thomas, the person in charge of the University of Lisanna, said that when the goal is composed of thousands of rocks, the consequences of impacting it are much more difficult than predicting a solid boulder.

Subina Raducan, a planetary scientist at the University of Bernes in Switzerland, said that if Dart hit a fragile gravel pile target, the meteorite pit will be formed within a few hours, and this process may take several months or even years to model.

Recently, DART has deployed a cube satellite size, which will use two optical cameras to record the collision process and its results. At the same time, James Webb and Hubble Space Telescope and 4 ground observatorys will monitor. Thomas said that if Dimorphos is a fragile gravel pile, the telescope should be able to capture its image within a few hours after the impact.

In the case of really asteroid threatening the earth, the solution is to hit the asteroid with sufficient strength to turn it, but at the same time, it cannot be too violent, resulting in the launch of small rock fragments to the earth. DART tasks will provide more data for scientists to improve the planet defense plan.

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