If anyone is going to avert Deep Impact from really happening, it’s NASA.
That might have been a comet in the movie, but killer asteroids could do just as well at bringing on Armageddon. Asteroids penetrate the atmosphere every day, but end up incinerated in the upper atmosphere before anyone can run for the nearest doomsday shelter. It’s the space rocks large enough to escape getting burned that are the reason the space agency’s Double Asteroid Redirect Test (DART), which recently announced its mission to divert a small asteroid from its Earth-bound course.
Even an asteroid that doesn’t have mass-extinction potential could mean dire consequences for Earth. DART is now entering its preliminary design phase, and its proto run, scheduled for October 2022, will target binary asteroid system Didymos (which appropriately translates to “twin” in Greek) as it creeps toward our planet. Didymos B orbits the larger Didymos A and is of a decent enough size to inflict serious damage should it strike our planet. NASA plans to take aim at the smaller asteroid in the system with a DART spacecraft around the size of your fridge, except appliances don’t zoom through space nine times faster than a bullet and crash into moving objects. The impact from the collision is predicted to slightly alter the asteroid’s total velocity before it has any chance to come hurtling towards us.
“A binary asteroid is the perfect natural laboratory for this test,” said DART program scientist Tom Statler. “The fact that Didymos B is in orbit around Didymos A makes it easier to see the results of the impact, and ensures that the experiment doesn’t change the orbit of the pair around the sun.”
Scientists back on Earth will analyze the impact and its effect on the orbit of Didymos B to determine whether we really could send much more threatening asteroids off course in the future. What may seem like an almost insignificant bump is believed to shift the asteroid’s path significantly over time—and away from Earth. After its initial launch, DART will continue using its built-in autonomous targeting system to zero in on intermediate asteroids that may not literally shake the planet but could still to obliterate an entire city. NASA has had its telescopic eye on these, which launched the Planetary Defense Coordination Office (PDCO) last year to identify and take action against any potentially hazardous comets and asteroids.
"DART is a critical step in demonstrating we can protect our planet from a future asteroid impact," said Andy Cheng, one of the leaders of the investigation team at the Johns Hopkins Applied Physics Laboratory, which is collaborating with NASA to develop DART. "With DART, we can show how to protect Earth from an asteroid strike with a kinetic impactor by knocking the hazardous object into a different flight path that would not threaten the planet."