NASA to test asteroid defense technique
According to NASA's press release, their asteroid deflection technique for planetary defense DART is moving from concept development to preliminary design phase.
"DART would be NASA's first mission to demonstrate what's known as the kinetic impactor technique -- striking the asteroid to shift its orbit -- to defend against a potential future asteroid impact. This approval step advances the project toward an historic test with a non-threatening small asteroid." -- Lindley Johnson, planetary defense officer at NASA Headquarters in Washington
DART's first target will be an asteroid Didymos which will move past Earth in 2022 and then again 2024. Didymos is a twin-asteroid, one part around half-mile in size and the other one 530 meters in size. DART's target is the smaller body.
"A binary asteroid is the perfect natural laboratory for this test," said Tom Statler, program scientist for DART at NASA Headquarters. "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."
According to Andy Cheng of The Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, the DART investigation co-lead, "DART is a critical step in demonstrating we can protect our planet from a future asteroid impact. Since we don't know that much about their internal structure or composition, we need to perform this experiment on a real asteroid. 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."
You can read the full press release here.