Our planet is constantly being bombarded with small pieces of debris, but these are usually burned or broken up long before they hit the ground. Once in a while, however, something large enough to do significant damage hits the ground. About 66m years ago, one such collision is thought to have ended the reign of the dinosaurs, ejecting vast amounts of dust and debris into the upper atmosphere, which obscured the sun and caused food chains to collapse. Someday, something similar could call time on humanity’s reign – unless we can find a way to deflect it.
Nasa’s Double Asteroid Redirection Test (Dart) mission is the first attempt to test if such asteroid deflection is a realistic strategy: investigating whether a spacecraft can autonomously navigate to a target asteroid and intentionally collide with it, as well as measuring the amount of deflection.
“This is the first step to actually trial a way of preventing near-Earth object impact,” said Jay Tate, the director of the National Near Earth Objects Information Centre in Knighton in Powys, Wales. “If it works, it would be a big deal, because it would prove that we have the technical capability of protecting ourselves.”