After intentional collision
Nasa announces: Dart probe has successfully deflected asteroid from its orbit
This NASA image shows the asteroid moon Dimorphos – eleven seconds before the impact of the “Dart” spacecraft
© NASA/Johns Hopkins APL/AFP
A success for NASA: The impact of the Dart probe in September has reduced the orbit of the asteroid moon Dimorphos, announced Nasa boss Bill Nelson.
The first deliberate collision of a spacecraft with an asteroid appears to have been a success and changed the orbit of the celestial body. The head of the US space agency Nasa, Bill Nelson, said on Tuesday that the impact of the Dart probe around two weeks ago had reduced the orbit of the asteroid moon Dimorphos. While it used to take Dimorphos eleven hours and 55 minutes to orbit its big brother Didymos, it now only takes eleven hours and 23 minutes.
“We showed the world that NASA is a serious defender of this planet,” Nelson said. The darts project might have sounded like a script for a movie. “But that wasn’t Hollywood.” It was the first maneuver in space ever to test the defense against an asteroid threatening Earth.
Nasa wants to save the earth with the “Dart” mission in an emergency
The refrigerator-sized space probe Dart crashed into the celestial body eleven million kilometers from Earth on September 26 at a speed of more than 23,000 kilometers per hour. Impressive images of the impact quickly emerged, captured by telescopes and a mini-satellite. However, it took two weeks to determine whether the asteroid’s orbit had been altered, and if so, to what extent.
NASA’s goal was to shorten the orbit of Dimorphos, which has a diameter of 160 meters and is about the size of an Egyptian pyramid, by up to ten minutes. This goal has now been significantly exceeded: the reduction is 32 minutes. In order to steer a dangerous asteroid past the earth in an emergency, only minimal course changes would be necessary with early intervention.
The probe for the spectacular “Double Asteroid Redirection Test” experiment, or Dart for short, was launched in California in November 2021. Dimorphos and Didymos do not pose a threat to Earth. However, they were ideal for testing a technology for deflecting celestial bodies.
The lessons of space history
Of the billions of asteroids and comets in our solar system, very few are classified as potentially dangerous to Earth. An impact is not expected for the next 100 years. However, it is considered probable that at some point a celestial body will impact the earth again.
This is also taught by space history: about 66 million years ago, the Chicxulub asteroid, about ten kilometers in size, hit what is now Mexico. It ensured a long winter and is associated with the extinction of the dinosaurs and three quarters of all other species at that time.
The impact of an asteroid the size of Dimorphos would only have regional effects. But it would have more force than any atomic bomb and could destroy an entire city.