Using a SpaceX Falcon 9 rocket, NASA launches a DART at a distant asteroid:
NASA launched a spacecraft Tuesday night on a mission to smash into an asteroid and test whether it would be possible to knock a speeding space rock off course if one were to threaten Earth.
The DART spacecraft, short for Double Asteroid Redirection Test, lifted off from Vandenberg Space Force Base atop a SpaceX Falcon 9 rocket in a $330 million project with echoes of the Bruce Willis movie “Armageddon.”
If all goes well, in September 2022 it will slam head-on into Dimorphos, an asteroid 525 feet (160 meters) across, at 15,000 mph (24,139 kph).
“This isn’t going to destroy the asteroid. It’s just going to give it a small nudge,” said mission official Nancy Chabot of Johns Hopkins Applied Physics Laboratory, which is managing the project.
We pause here to refresh ourselves on the law of unintended consequences... Done.
Here's how the plan works:
Dimorphos orbits a much larger asteroid called Didymos. The pair are no danger to Earth but offer scientists a way to measure the effectiveness of the collision.
Dimorphos completes one orbit of Didymos every 11 hours, 55 minutes. DART’s goal is a crash that will slow Dimorphos down and cause it to fall closer toward the bigger asteroid, shaving 10 minutes off its orbit.
The change in the orbital period will be measured by telescopes on Earth. The minimum change for the mission to be considered a success is 73 seconds.
Neither asteroid is a threat to Earth, nor is there any currently known asteroid ("that we know of!") on a collision course with us. But, we're happy Earthlings with the wherewithal for "planetary defense" are planning and working on it just in case.
Also, the collision will be streamed:
Ten days beforehand, DART will release a tiny observation spacecraft supplied by the Italian space agency that will follow it.
DART will stream video until it is destroyed on impact. Three minutes later, the trailing craft will make images of the impact site and material that is ejected.
So, good luck, DART. We'll mark our calendar for September 2022.
(Illustration: DART spacecraft with deployed solar arrays/ NASA)
