When a spacecraft slammed into an asteroid last month, it pushed it closer to its companion and sped up its orbit by about 32 minutes. It’s a huge milestone for the field of planetary defense; it establishes that it may be possible for humans to significantly change the path of a potentially hazardous asteroid — especially if we have warning that one is on the way.
When the Double Asteroid Redirection Test (DART) mission sent a spacecraft crashing into its surface on September 26th,…