NASA launches spacecraft to stop an asteroid from hitting the Earth

LOS ANGELES - NASA launched a spacecraft Tuesday night on a mission to crash into an asteroid and test if it would be possible to deflect a space rock at high speed if one threatened Earth.

Short for Double Asteroid Redirection Test, the DART spacecraft took off from Vandenberg Space Force Base on a SpaceX Falcon 9 rocket in a $ 330 million project with echoes of the Bruce Willis film "Armageddon."

If everything goes well, in September 2022, it will crash head-on into Dimorphos, a 525-foot (160-meter) wide asteroid 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, managing the project.

Dimorphos orbits a much more giant asteroid called Didymos. The pair pose no danger to Earth but offer scientists a way to measure the effectiveness of the collision. Dimorphos completes an orbit of Didymos every 11 hours and 55 minutes. DART's goal is a collision that will slow Dimorphos and cause it to fall closer to the giant asteroid, reducing its orbit by 10 minutes.

Will measure the change in the orbital period with telescopes on Earth. The minimum difference for the mission to be considered a success is 73 seconds.

The DART technique could help alter the course of asteroid years or decades before it reaches Earth with the potential for catastrophe.

Chabot said, a little push "would add up to a big change in its future position, and then the asteroid and the Earth wouldn't be on a collision course." Scientists continuously search for asteroids and plot their trajectories to determine if they could hit the planet.

"Although there isn't a currently known asteroid that's on an impact course with the Earth, we do know that there is a large population of near-Earth asteroids out there," shared Lindley Johnson, planetary defense officer at NASA. "The key to planetary defense is finding them well before they are an impact threat."

DART will take ten months to reach the asteroid pair. The collision will occur about 11 million kilometres from Earth. Ten days earlier, DART will launch a small observation spacecraft provided by the Italian space agency that will follow it. DART will transmit video until it is destroyed upon impact. Then, three minutes later, the tracking craft will take pictures of the impact site and the ejected material.