Humanity is one step closer to avoiding extinction by an asteroid impact.
Last September 26, 2022, NASA’s DART probe successfully collided with its target, the asteroid Dimorphos, altering the latter’s course and destroying itself in the process.
DART, or Double Asteroid Redirection Test, was the first-ever mission to investigate altering an asteroid's motion in space through impact with a spacecraft.
The DART spacecraft was launched from Earth in November 2021 with the intent to impact Dimorphos, a small asteroid moonlet orbiting the near-Earth asteroid Didymos, sometime between September 26, 2022, and October 1, 2022.
The spacecraft accelerated at about 21,600 kilometers per hour when it collided with Dimorphos.
Because of the spacecraft's high speed and kinetic energy, the energy of the DART spacecraft was transferred to the Dimorphos asteroid on impact, slightly moving its orbit inwards. This is Newton’s Third Law in action: "For every action, there is an equal and opposite reaction."
Spacecrafts are usually used for communication, space exploration, and observation. The DART spacecraft’s primary objective was to investigate a method for defending the planet against incoming space rocks such as asteroids and comets. In other words, this spacecraft’s mission is to ram itself into a space rock to alter its course.
Even if Dimorphos is not at risk of impacting Earth, the DART mission demonstrated how we could deflect space rocks that may impact Earth in the future. In addition, as Dimorphos and Didymos were not on a path to intersect with Earth before the demonstration, it made them the perfect “test subjects.”
We are entering an era where we have the increased ability to protect ourselves from a dangerous asteroid impact, maybe even one as catastrophic as the asteroid that caused the extinction of the dinosaurs. Once the DART technology is perfected, we can protect ourselves from more existential threats to come – we won’t go extinct, unlike the dinosaurs.
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