“We don’t need Bruce Willis”: NASA knocks asteroid off-course

Back in September 2022, a specially-built spacecraft collided with the asteroid Dimorphos about 10,000 km away from earth. Nearly four years later, NASA has confirmed the impact altered both its course, and that of a larger asteroid that Dimorphos orbits, which marks the first time in history that humans have adjusted the path of a celestial body.

More than a decade in the making, the Double Asteroid Redirection Test has successfully done what many had thought was surely the answer to a massive rock hurtling towards earth. Despite the complex nature of astrophysics, it turns out that “just blast something towards it” could indeed be a way of saving us from going the way of the dinosaurs. As Dr Preeti Cowan from University of Auckland explains, although the impact only shortened the pair’s orbit around the sun by a fraction of a second, this all adds up pretty quick:

“Imagine a really long road trip. If you nudge your steering wheel slightly at the beginning, after hundreds of kilometers, you're going to end up somewhere completely different. It's a lot like that in space as well. This tiny change in velocity is going to make a huge difference over time. If we nudge it years in advance of a potential impact, it's going to miss earth entirely.”

Along with the good news that there is actually something we can do about impending planetary destruction, the DART mission is also a win for the continued existence of non-profit space research. At a time when space is increasingly becoming the domain of privately-own, profit-driven corporations, Dr Cowan explains why having something like NASA remains so important:

“Publicly-funded agencies can take on long-term projects that will end up benefiting everyone on earth. This is also supported by the European Space Agency, who are going to go back and visit this asteroid to see what the DART mission’s impact was a few years on. There are other missions to asteroids purely so that we can understand what they're made of, so we have a better understanding of how we can deflect one if it should come our way.”

With ongoing fears about the future of NASA after the agency narrowly avoided drastic cuts to its budget, the fact it’s able to point to the success of the test is surely welcome news for its supporters.