NASA this week successfully did what it normally tries to avoid, and destroyed one of its own spacecraft — by ramming it into an asteroid. It was the first step in an experiment that could one day spare humanity from the fate of the dinosaurs by knocking a celestial threat off course. In an age when science is too often under attack from climate change deniers, anti-vaxxers and others, it’s a timely reminder that scientists are, in fact, on the good side.
The space agency’s Double Asteroid Redirection Test, aptly given the acronym DART, aimed a refrigerator-sized spacecraft at a football-stadium-sized asteroid and, on Monday evening, scored a bull's-eye. The idea is to see whether striking the asteroid, called Dimorphos, might change its trajectory. Dimorphos circles a larger asteroid in a known orbit, so NASA should be able to ascertain within a few months whether it has successfully altered that orbit — which would be a first in human history.
The stakes couldn’t be higher. There are no non-avian dinosaurs in today’s zoos because, 66 million years ago, a six-mile-wide asteroid struck Earth in what is now Mexico, raising smoke and dust that blotted out the sun worldwide for years and starved them into extinction.
