China is expanding its planetary defense efforts with a new asteroid detection network aimed at spotting dangerous space rocks long before they become a threat to Earth, according to the South China Morning Post.
SCMP writes that the planned system will pair a network of powerful ground-based telescopes with satellites in orbit, giving scientists the ability to monitor the sky around the clock. Space-based sensors can also detect asteroids approaching from the sun’s direction—objects that are especially difficult for Earth-based observatories to see.
Li Mingtao, the chief scientist overseeing the project, said there are currently no known asteroids expected to strike Earth. Even so, he cautioned that many medium-sized objects capable of causing widespread regional destruction have yet to be discovered.
According to Li, astronomers have already identified more than 95% of near-Earth asteroids larger than one kilometer in diameter, which are large enough to trigger global consequences. But the search is far less complete for smaller bodies. Scientists estimate they’ve located only about 45% of asteroids roughly 140 meters across—large enough to wipe out a city or devastate an entire region.
Li said these missing asteroids represent the biggest concern because they are difficult to detect until they are relatively close, and some can approach from blind spots created by the sun’s glare.
If the system identifies a potentially hazardous object, it will analyze the asteroid’s orbit, estimate the odds of an impact, and notify authorities if the risk reaches a dangerous level.
China has also stepped up research into planetary defense in recent years, hiring specialists and refining software used to predict collision risks. Officials believe the most effective defense remains a kinetic impact mission—crashing a spacecraft into an asteroid to slightly alter its course before it reaches Earth. Other proposed methods, such as lasers, particle beams, or using a spacecraft’s gravity to tug an asteroid off course, remain largely theoretical and would generally require much longer to work.