China selects asteroid for 2025 planetary defense experiment.

China has selected a small, near-Earth asteroid as the target for an upcoming planetary defense mission, which will include both an observer and an impactor spacecraft tucked inside a Long March 3B rocket. The impactor spacecraft will smash into the small asteroid, hoping to deviate its trajectory by 1 to 2 inches (3 to 5 centimeters). China's planetary defense test is similar to NASA's DART mission, which slammed into an asteroid in September 2022 and successfully altered its trajectory.