China is looking to take a further step in global protection of the Earth by slamming into an asteroid with a kinetic projectile traveling at Mach 26, or almost twenty thousand miles per hour, in order to alter its path, or even to break up its structure The effort is still in the early planning stages. The program has been presented in a paper which is now under review by the Chinese-language Journal of Space Exploration.
If implemented, the proposed program would go further than NASA’s “Dart” project, which in 2022 succeeded in hitting an asteroid, Dimorphus, which was orbiting a larger asteroid, Didymus The envisioned spacecraft is expected to hit its target at more than 9 km (5.6 miles) per second, compared with Dart’s 6.1 km/s. At the same time there will be another spacecraft in the vicinity to observe the asteroid before, during, and after the collision, tracking changes in its orbit.
“Dart was the first to demonstrate asteroid deflection by kinetic impact in space,” wrote the researchers from the China National Space Agency, “but it did not directly change an asteroid’s orbit around the Sun relative to Earth, making it different from a real planetary-defense scenario.” From later observations it was, however, in fact shown that Dart had altered the orbit of Dimorphus somewhat, changing the time in which it orbited Didymus from 11 hours 55 minutes to 11 hours, 23 minutes.
