Nasa has launched a spacecraft that will intentionally crash into an asteroid to test the Earth’s defence against any future threats.
A SpaceX Falcon 9 rocket lifted off from California’s Vandenberg Space Launch Complex at 10.20am, Dubai time, on Wednesday, carrying the Dart (Double Asteroid Redirection Test) spacecraft.
At 10.27am, the payload fairing carrying the spacecraft successfully separated from the rocket. At 11.16am, the spacecraft separated, beginning an 11-month journey to the Didymos asteroid system.
Dart will target a pair of asteroids that orbit close to each other. The binary asteroid system is located 11 million kilometres from Earth.
The spacecraft will smash into a 160-metre-wide “moonlet” Dimorphos between September and October, forcing it and its larger companion, Didymos, to shift slightly off course.
The spacecraft will crash into the asteroids at a speed of 24,000 kph - fast enough to travel from New York to Paris in 15 minutes.
“It’s very rare for an asteroid to impact Earth, but it’s something we want to know very well ahead of time. We’re out there searching the skies and developing a catalogue of asteroids and comets that can come near Earth,” Lindley Johnson, planetary defence officer at Nasa, said.
The asteroids do not pose any threat to Earth, but the mission would help Nasa secure technology that can be used in any future cosmic threats.
Ten days before the impact, the spacecraft will release a CubeSat, a type of miniaturised satellite for space research, that would capture images of the event.
Nancy Chabot, Dart co-ordination lead at Johns Hopkins Applied Physics Laboratory, said they would also use ground telescopes to make observations.
“If there was an asteroid that was a threat to the Earth, you’d want to do this technique many decades in advance, such that you would give this asteroid a small nudge, which would add up to a big change to its future position and then the asteroid and Earth wouldn’t be on a collision course,” she said.
The spacecraft will autonomously crash into the asteroid after tracking it with a special navigation technology Johns Hopkins engineers have built.
Four hours before impact, the technology would be switched on, allowing Dimorphos to appear as a small pixel in the cameras.
Engineers are hoping a live stream of the video would be possible.
Scientists have been tracking near-Earth objects for decades to ensure none are on a collision course with the planet.
About 65 million years ago, an asteroid crashed on Earth and killed 70 per cent of all species, including dinosaurs.
Researchers believe the collision, known as the Chicxulub Impact Event, created devastating tsunamis, earthquakes, volcanic eruptions and wildfires.
In 2013, an asteroid crashed into the Russian city of Chelyabinsk. The asteroid exploded after entering Earth’s atmosphere and released energy equivalent to 500 kilotonnes of TNT.
The incident caused more than 3,600 windows to shatter, injuring more than 1,000 people.