The destruction of a multi-million dollar spacecraft is normally not something to celebrate. But the crash of NASA’s Double Asteroid Redirection Test (DART) spacecraft on an asteroid is a significant exception.
On Monday, NASA announced that DART had collided with Dimorphos, a small body just 160 meters in diameter, which orbits a larger asteroid called Didymos, 6.8 million kilometers from Earth. This deliberate collision of a car-sized spacecraft with an asteroid – the equivalent of a golf cart traveling 15,000 miles per hour and crashing into the side of a football stadium – is an extremely impressive technical feat. This is the first step towards developing the means to divert an asteroid from a collision course with Earth.
All of this may seem pointless, especially since there are no known large asteroids that have a significant chance of hitting Earth in the next century. Yet, at the same time, it’s important to note that the threat is not imaginary – although it has been the subject of several Hollywood blockbusters. After all, the dinosaurs were probably wiped out by the impact of an asteroid hitting Earth 65 million years ago. As MIT Technology Review points out: “Humans are understandably eager to avoid the [dinosaurs’] spell.’
The researchers believe that DART could have shortened Dimorphos’ orbit around Didymos by one percent, or about 10 minutes. This would be enough to make a significant difference in the trajectory on which the asteroid is moving. And so this could show how we might be able to deflect an asteroid heading towards Earth.
Scientists won’t know the full picture for four years, when the European Space Agency launches its Hera mission. This mission will study the impact of DART on the orbit of Dimorphos, the diameter and depth of the DART crater, and the interior structure and composition of Dimorphos. This should give us a better understanding of what it takes to move an asteroid.
In the meantime, ground-based telescopes, alongside the Hubble and James Webb Space Telescopes, will track what happens next and watch for changes in Dimorphos’ orbit.
This investment in planetary defense represents an impressive commitment to long-term thinking. It’s no understatement to say that what NASA and the European Space Agency are doing right now could enormously benefit people for centuries to come. It must be seen as part of humanity’s rational and conscious attempt to exert ever greater mastery over nature. And it will allow us to plan more rigorously for the future.
Patrick Michel, planetologist at the National Center for Scientific Research and principal investigator of the Hera mission, best captured the spirit of scientific adventure of the whole company. “It’s very exciting because anything could have happened,” he said after DART’s successful impact.
We don’t know how it will turn out. But for Michel, and others involved in the DART and Hera missions, this uncertainty is an opportunity, not a threat. Missions are an opportunity to experiment and take risks, deep in space. And, through this process, we can potentially develop knowledge that will greatly benefit future generations.
All of this represents a welcome response to the fatalism that dominates our historical moment. These scientists are not passively waiting for the future to happen. They try to exert some control over her here and now. And that is surely something worth celebrating.
Norman Lewis is editor and managing director of Futures Diagnosis.
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