Nasa says Dart mission succeeded in shifting asteroid’s orbit

A spacecraft that plowed into a small, harmless asteroid millions of miles from Earth succeeded in shifting the orbit of the space rock, Nasa said on Tuesday, announcing the results of its first such test.

The US space agency strategically launched the Double Asteroid Redirection Test ("Dart") spacecraft into the path of the asteroid, thereby throwing it off course.

Nasa hopes to be able to deflect any asteroid or comet that comes to pose a real threat to Earth.

The Nasa administrator, the former astronaut and Democratic Florida senator Bill Nelson, said: "We showed the world that Nasa is serious as a defender of this planet."

Lori Glaze, director of Nasa's planetary division, said: "Let's all just take a moment to soak this in. We're all here this afternoon because for the first time ever, humanity has changed the orbit of a planetary body."

Two famous Nasa telescopes, Webb and Hubble, captured the moment the spacecraft collided with the moonlet asteroid on 26 September. It took days of observation to determine how much the impact altered the path of the 525ft asteroid around its companion, a much bigger rock.

In a statement following the test, Nasa said Dart "intentionally crashed into Dimorphos, the asteroid moonlet in the double-asteroid system of Didymos. It was the world's first test of the kinetic impact mitigation technique, using a spacecraft to deflect an asteroid that poses no threat to Earth, and modifying the object's orbit.

"Dart is a test for defending Earth against potential asteroid or comet hazards."

Dart altered the orbit of the Dimorphos asteroid by 32 minutes. Glaze said the minimum requirement for changing the orbital period was "really only 73 seconds".

Last year, in a test that cost $325m, another Dart spacecraft, roughly the size of a vending machine, was destroyed when it slammed into an asteroid 7m miles away, at 14,000mph.

On Tuesday, public figures were quick to congratulate Nasa on the success of the second test.

In a tweet, the vice-president, Kamala Harris, said: "Congratulations to the team at Nasa for successfully altering the orbit of an asteroid. The Dart mission marks the first time humans have changed the motion of a celestial body in space, demonstrating technology that could one day be used to protect Earth."