For the first time, the US space agency NASA launched a probe that is intended to deliberately crash into an asteroid and thereby change its trajectory.
The aircraft took off on Wednesday morning German time using a "Falcon 9" rocket from the US state of California.
"Asteroid Dimorphos: We'll get you," wrote NASA on Twitter shortly after the launch.
The probe is scheduled to hit the asteroid Dimorphos next October.
NASA hopes that the "Dart" (Double Asteroid Redirection Test) mission, which costs around $ 330 million (around EUR 290 million), will provide information on how the earth could be protected from approaching asteroids.
27,000 asteroids near Earth
According to NASA calculations, Dimorphos, a kind of moon of the asteroid Didymos with a diameter of around 160 meters, does not pose a threat to Earth at the moment - and the mission is designed so that the asteroid only uses a camera even after the probe hits on board should not pose any danger.
After the impact, the approximately twelve-hour orbit of Dimorphos is said to be at least 73 seconds and possibly up to ten minutes shorter.
The Esa “Hera” mission is scheduled to start in 2024 to investigate the effects of the impact more closely.
At the moment, scientists are not aware of any asteroid that could speed directly towards Earth in the foreseeable future - but researchers have identified around 27,000 asteroids in the vicinity of our planet, around 10,000 of which are more than 140 meters in diameter.