When a spacecraft collided with an asteroid last month, it pushed the spacecraft closer to its partner and accelerated its orbit by around 32 minutes. It’s a tremendous step forward in the subject of planetary defence; it proves that humans may be able to dramatically alter the route of a potentially harmful asteroid — particularly if we have advance information that one is on its way.
On September 26th, observatories on Earth and in space were monitoring the event when the Double Asteroid Redirection Test (DART) mission sent a spacecraft smashing onto its surface. Now, preliminary results from those observatories reveal that DART accomplished its mission. Before the collision, the asteroid Dimorphos orbited its considerably bigger companion asteroid, Didymos, for around 11 hours and 55 minutes. The same journey takes now 11 hours and 23 minutes.
