Our space neighborhood is filled with comets, meteors, asteroids, and other random bits of rocky flotsam and jetsam, any one of which could come plummeting through the Earth’s atmosphere and slam into our planet. Over Earth’s long history, many objects have done precisely that. That reality is of no small concern, because if the object is large enough, the impact could have catastrophic, climate-altering consequences. Some scientists theorize, for example, that the extinction of the dinosaurs occurred because of the after-effects of a gigantic and devastating meteor strike that occurred 65 million years ago.
The fact that humans haven’t had to deal with a similar random, collision-caused disaster has been the product of sheer dumb luck–until now. Thanks to the scientists and engineers at NASA, and the successful test on Monday of a suicidal spacecraft called the Double Asteroid Rendezvous Test (“DART”) probe, we’ve finally got a fighting chance.
The DART mission sought to show that the paths of killer asteroids could be deflected away from Earth by being rammed by a spacecraft. The target of the mission, at a distance about 7 million miles from our planet, was an asteroid called Dimorphos, and the goal was to change its orbit around a larger asteroid called Didymos. The DART probe, which was about the size of a golf cart and weighed 1,320 pounds, slammed into Dimorphos at a brisk 14,000 miles per hour rate, with the goal of nudging the asteroid into a speedier orbit around Didymos. Happily, the DART probe hit the Dimorphos bullseye, and as it approached it provided a continuous stream of photos, like the one above, that made the asteroid target look like a rock-studded egg in space. The ultimate crash of the DART into the target also was captured by many Earth-based telescopes. You can see the video of the collision taken from one telescope here.
So, did the ultimate sacrifice willingly undertaken by the DART probe successfully change the orbit of Didymos, as we hhope? We don’t know for sure, yet, but we’ll find out as the asteroid is monitored, and its orbit path is measured, over the next few months. But just being able to navigate a golf cart-sized spacecraft moving at 14,000 miles an hour into a moving asteroid seven million miles away is a pretty good start to developing a planetary defense system that will protect our species, and other inhabitants of planet Earth, from the ravages of killer asteroids.