On Tuesday, NASA announced that its test to deflect the asteroid Dimorphos two weeks ago succeeded beyond expectations - changing the asteroid's orbital path around a larger asteroid, Didymos, by 32 minutes. NASA official Lori Glaze stated, "For the first time ever, humanity has changed the orbit of a planetary body," and, "we are capable of deflecting an asteroid."
On Sept. 26, NASA's spacecraft collided with Dimorphos at 14K mph in a mission known as DART (Double Asteroid Redirection Test). The intent was to see if a near-Earth asteroid could be successfully deflected; a change in the trajectory of 10 minutes would have been considered a success.
While this mission may seem aimed at combating a far-fetched hazard, defending the planet from asteroids is incredibly important. Investing in planetary defense missions like DART brings us closer to preventing catastrophic events that have changed the course of life on Earth many times in the past.
If NASA is going to invest taxpayer funds into a low-probability, a high-impact threat like deflecting asteroids, a good offense is better than a strong defense. This means developing an aggressive early warning system and even being able to pulverize potential intruders. Asteroid defense is an expensive undertaking, so let's get it right.