Asteroids
© Pixabay

Despite an admission last year that it may be impossible to stop the 8.8 ton asteroid Bennu from annihilating life on Earth, the perennial optimists at NASA have nevertheless granted SpaceX a $69 million contract to assist in the Double Asteroid Redirection Test (DART), intended to save Earth from interstellar armageddon. The test, tentatively scheduled for June 2021, will have Elon's Musketeers crashing a kinetic impactor - in this case, a spacecraft equipped with cameras and solar panels - into a small moonlet accompanying Didymos, an 800-meter-long near-Earth asteroid. NASA notes that the moonlet, dubbed "Didymoon" by scientists, "is more typical of the size of asteroids that could pose a more common hazard to Earth" than its massive chaperone.

The goal, NASA says, is to launch the DART spacecraft atop a SpaceX Falcon 9 rocket that will then make its way to Didymos and Didymoon to attempt to alter the latter's trajectory in a rehearsal for what could one day be a high-stakes game of cosmic bumper cars. "By using solar electric propulsion," NASA says, "DART will intercept the asteroid Didymos' small moon in October 2022, when the asteroid will be within 11 million kilometers of Earth." Meanwhile, Earthlings will watch with bated breath.

"The collision will change the speed of the moonlet in its orbit around the main body by a fraction of one percent," NASA promises, "enough to be measured using telescopes on Earth."

DART and Didymos
© NASA
Should the test prove successful, it could pave the way for the development of similar tactics intended for larger targets. Should it fail, then we'd better figure out a new plan because eventually some massive asteroid is going to get lucky. Given NASA's inability to detect some of these falling objects until they've already struck Earth, we can at least rest assured that the deep impact will likely be over before we have time to worry about it.