Forget what you’ve seen in the movies – if we discovered an asteroid on a collision course with Earth, there is very little we could do. Luckily, that possibility is remote, but nonethless the people at NASA have decided to be prepared.
The Double Asteroid Redirection Test (DART) has passed its first hurdle and is now moving from concept development to preliminary design phase. This could be the first-ever mission to demonstrate an asteroid-deflection technique.
“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,” Lindley Johnson, planetary defense officer at NASA Headquarters in Washington, said in a statement. “This approval step advances the project toward a historic test with a non-threatening small asteroid."
The target is a binary asteroid called Didymos, which is made of two objects orbiting each other. Didymos A is 780 meters (2,559 feet) in size, while Didymos B is 160 meters (525 feet). DART will hit Didymos B, so that we can observe the effects of the deflection safely.
“A binary asteroid is the perfect natural laboratory for this test,” explained 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.”
The probe, which is the size of a fridge, is expected to strike the asteroid at about 6 kilometers (3.7 miles) per second, slightly changing its orbit. Scientists will monitor the changes to work out the exact effect of such a technique.
“DART is a critical step in demonstrating we can protect our planet from a future asteroid impact,” added investigation co-lead Andy Cheng of The Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. “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.”
While this has potential, DART has not had any funding allocated in next year’s NASA budget. Didymos will fly near our planet in 2022 and 2024, so the researchers need to make a good case for the probe at all the next approval checkpoints.
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