Asteroids are small, rocky objects that orbit the sun. Extremely dangerous asteroids are rare. However, some asteroids that collide with Earth every 1,000 to 10,000 years have the potential to obliterate entire cities. As a result, scientists have long sought a way to prevent asteroids from hitting Earth.
The researchers used a computer simulation to test their theory and published their findings on May 22 in the online journal Scientific Reports. The theory consists of sending an unmanned craft to space to deflect an asteroid by colliding with it at a high speed. To impart enough force to deflect the asteroid, the spacecraft must have a certain mass. One way for the spacecraft to bulk up sufficiently is to collect rocks from near-Earth asteroids on its way to meet its target.
The computer simulation included an imagined, eight-tonne spacecraft dubbed the “enhanced kinetic impactor,” or EKI. In the simulation, it was launched into space on October 7, 2021, on a Long March 5 rocket. The researchers were able to simulate the EKI crashing into a near-Earth asteroid, known as Apophis, at a high speed of more than 42,000 kilometers per hour, causing the asteroid to be deflected away from Earth. The collision was so powerful, it caused Apophis to move more than 1,800 kilometers off its course in the simulation.
According to Li Mingtao, the study’s lead author, the team wanted to find an alternative to “controversial nuclear explosions,” which have been proposed by NASA as a method to deflect dangerous asteroids away from Earth.
A Beijing-based scientist, who was not involved in the study and spoke on the condition of anonymity, called the report’s method a “smart strategy of turning one asteroid against another,” the South China Morning Post reported.
“It [EKI] is more about trapping, slipping and deflecting the attack than throwing punches,” he added.
The scientist also pointed out that even though the strategy works well in theory, the technology required for the unmanned aircraft to build up mass by collecting rocks of up to 10 meters in diameter from passing asteroids has not been tested in actuality.
Professor Wu Yunzhao, a researcher in the laboratory of planetary sciences at the Purple Mountain Observatory in Nanjing, also noted that deflecting asteroids requires international cooperation and most likely cannot be achieved by China alone.
“The threat of an asteroid impact is real and serious, and preventing it requires long-term planning and preparation,” he said, the South China Morning Post reported. “It also needs global cooperation, because no country has the ability and resources to do it alone.”