NASA has successfully launched a probe to investigate the Bennu asteroid, which threatens to strike Earth in the late 22nd century.
The Osiris-Rex craft lifted off from Cape Canaveral just after midnight (BST), propelled by a United Launch Alliance Atlas V rocket.
The probe will rendezvous with Bennu in 2018, when it will begin a two year mapping exercise, before capturing a sample to return to Earth in 2023.
There is a 0.037% chance that Bennu will collide with Earth in the next century, triggering damage comparable to 3bn tons of explosive.
The asteroid has been edging closer to Earth’s orbit for decades, but in 2135 it will pass between us and the moon for the first time.
The fly-by could see the asteroid’s orbit realigned to cross paths with Earth’s later in the century.
One of the craft’s key tasks will be to investigate an unusual phenomenon known as the Yarkovsky effect.
Dante Lauretta, professor of planetary science at Arizona University, told the Sunday Times that the force “acts on an asteroid when it absorbs sunlight and then radiates it back into space as heat. It acts like a small thruster, constantly changing its course.”
Space reported that Lauretta said in a press conference: “[The Yarkovsky effect] acts like a thruster and changes the trajectory of the asteroid.
“If you want to be able to predict where an object like Bennu is going to be in the future, you have to account for this phenomenon, and we’re going to provide the best-ever scientific investigation of this fascinating concept.”
The research team is hoping to use the samples to search for organic molecules, potentially shedding light on how life on Earth started.