It used to take Dimorphos eleven hours and 55 minutes to orbit its big brother Didymos, now it takes eleven hours and 23 minutes. “We showed the world that NASA is a serious defender of this planet,” Nelson said.
The DART space probe crashed into the celestial body on September 26 at a speed of more than 23,000 kilometers per hour. It was the first maneuver ever in space to test the defense against an asteroid threatening Earth. In order to steer a dangerous asteroid past the earth in an emergency, only minimal course changes would be necessary with early intervention.
target exceeded
NASA’s goal was to shorten Dimorphos’ orbit by up to ten minutes. This goal has now been significantly exceeded: the reduction is 32 minutes.
Until now, similar missions had only been seen in the cinema – keyword “Armageddon”. Away from fiction, astronomers are currently not aware of any threatening asteroids. Still, NASA wanted to be prepared. “We are now entering a new era for humanity where we may have the ability to protect ourselves against an asteroid impact,” NASA executive director Lori Glaze said after the maneuver.
NASA boss sees turning point
“This mission shows that NASA is trying to be prepared for whatever the universe throws at us. NASA has proven that we take defending the planet seriously,” said Space Agency chief Bill Nelson. He called the mission’s success a “watershed moment” in protecting humanity from an asteroid impact. In the coming weeks and months, the impact of the collision will now be further investigated. In 2024, the similar mission “Hera” of the European Space Agency (ESA) is to start for even more detailed exploration.
Relief already on the day of the mission
In the images transmitted back to Earth by the probe’s camera, the asteroid Dimorphos only became visible as a bright point about an hour before impact, then grew in size and finally showed up with surface detail and shading – until the camera was destroyed on impact and that picture displayed a red error.
At the end of September there was relief in the NASA control center. Traveling at 4 miles per second, the probe had been on autopilot for the last few minutes, and it wasn’t entirely clear if it would actually hit the asteroid.
distraction instead of destruction
NASA’s $325 million Double Asteroid Redirection Test (DART) mission put “Earth’s Future Safety” at stake for NASA. It is the first time that a dangerous object has been pushed out of the way with a direct experiment, said NASA Science Director Thomas Zurbuchen in advance. The DART probe was launched last November with a “Falcon 9” rocket from the US state of California.
experiment without danger
There was no danger in the experiment. Dimorphos, about 160 meters in diameter, and the larger 780-meter asteroid Didymos, which Dimorphos orbits, were at least about 11 million kilometers from Earth. Had the spacecraft missed the asteroid moon, it would have had enough fuel for a second attempt in two years.
The DART mission was accompanied by telescopes on Earth and the James Webb Space Telescope, as well as cameras on site. The probe’s own camera system sent images of Dimorphos to Earth up to the point of impact. After that, a toaster-sized satellite, which undocked from the DART spacecraft a few weeks ago, should take over, fly past the collision site and provide close-up images.
27,000 asteroids near Earth
In 2024, ESA will send the Hera probe on a two-year voyage to study the site of the collision and the surface of Dimorphos in more detail. For the next 100 years, scientists do not see any asteroid threatening Earth. If you wait long enough, there will be an object, said Zurbuchen. Scientists have identified around 27,000 asteroids near Earth, around 10,000 of which are more than 140 meters in diameter.
An asteroid impact has already happened. 66 million years ago, the Chicxulub asteroid, which was around 10 kilometers in diameter, struck what is now Mexico, causing a permanent winter and being associated with the extinction of the dinosaurs.