On the 11th local time, the National Aeronautics and Space Administration (NASA) held a press conference on the "Double Asteroid Redirection Test" (DART) mission and announced that the agency's test mission of using spacecraft impact to push a distant asteroid out of orbit was successful. This test shows that humans can use the science and technology they have mastered to avoid the risk of asteroids hitting the Earth in the future. NASA chose to impact on a double asteroid system, in which one asteroid is surrounded by another smaller satellite. The diameter of the main asteroid "Didymus" is about 780 meters, and the diameter of its small satellite "Didymus" is about 160 meters, which is located in the orbit about 1 km away from the main asteroid. Taking "Dimovos" and "Dimovos" as the target asteroids has been carefully selected. Neither of them is in the orbit intersected with the Earth, and the slight change of their orbits will not increase this risk. On September 26, the test was successfully carried out, and the images sent back by the spacecraft showed that the spacecraft had accurately hit the "body" of the "Dimovos" asteroid. The energy generated by the collision, together with the recoil of the ejected particles generated by the collision, has greatly changed the path of "Dimorphus" in space. After about two weeks of continuous observation and data analysis, NASA announced that before the impact, "Dimovos" circled "Dimovos" about every 11 hours and 55 minutes. After the impact, according to astronomical observations, the current orbital operation time is 11 hours and 23 minutes, 32 minutes less than before. Now, the orbit of "Dimorphus" is slightly close to "Dimorphus". According to NASA's standards, the minimum requirement for successful testing is 73 seconds, which has been greatly exceeded this time. According to NASA, the current scientists will focus on analyzing the "splash" of the impact mission, that is, the debris generated when the aircraft hits the asteroid at high speed. NASA said that the recoil force brought by the splash enhanced the thrust of the aircraft hitting the asteroid, which is similar to the air flow ejected by a balloon and can push the balloon forward in the opposite direction. In order to further understand the recoil force of the splash, we must first understand the physical characteristics of the asteroid. When NASA was carrying out the impact mission, the spacecraft LICIACube of the Italian Space Agency also flew along, taking photos and recording the mission process. Scientists can further understand the asteroid "Dimorphus" by analyzing these images. In October 2024, the European Space Agency will launch a space probe to closely and carefully assess the impact of this impact test on asteroids. (Liu Xinshe)