It is about nothing less than the security of the earth and the survival of mankind. In principle, it can happen at any time that a large asteroid is discovered that is on a collision course with our planet. So large that an impact would cause such devastation that the survival of mankind is in question. The astronauts want to be prepared for this dramatic moment. NASA's "Dart" (Double Asteroid Redirection Test) mission is a first concrete step.
What sounds like something out of a Hollywood film is a real project: next Monday (September 26), for the first time, a probe from the US space agency is to crash directly and intentionally into an asteroid, thereby changing its trajectory. "'Dart' is the first mission that tries to use a direct experiment to push a dangerous object out of the way," says NASA Science Director Thomas Zurbuchen.
All of this is strongly reminiscent of Hollywood films such as "Armageddon - The Last Judgment", in which in 1998 stars such as Bruce Willis and Ben Affleck destroyed an asteroid that was heading straight for Earth in a very short time using a complicated and dangerous maneuver. But: NASA's mission, which costs around 330 million dollars, is unmanned and the target asteroid Dimorphos is not racing towards Earth either, but according to NASA calculations it currently poses no danger. It is a first cautious attempt to see whether it is possible could be to change the trajectory of an asteroid in this way. NASA hopes to gain insights into how the earth could be protected from approaching asteroids.
The space agency has been dealing with this for many years. An asteroid impact around 66 million years ago, for example, is considered by scientists to be the leading theory as to why the dinosaurs became extinct. Scientists are not currently aware of any asteroid that could be heading straight for Earth any time soon, but researchers have identified around 27,000 asteroids near our planet, around 10,000 of which are more than 140 meters in diameter.
The "Dart" probe, launched in November from the US state of California with the help of a "Falcon 9" rocket, has been on its way to its target for around ten months. "Asteroid Dimorphos: We'll get you," Nasa tweeted shortly after launch. According to NASA, the probe will only be able to target Dimorphos with its camera about an hour and a half before the impact. Directing the flying object precisely into the asteroid is "incredibly challenging," says NASA manager Evan Smith.
About 160 meters in diameter, Dimorphos is a type of moon of the larger asteroid Didymos. The mission is designed in such a way that both asteroids should not pose any danger even after the impact of the probe, which only has one camera on board.
After the impact, Dimorphos' approximately 12-hour orbit is expected to be at least 73 seconds shorter and possibly up to 10 minutes shorter. That's when the real work begins for the scientists: investigating what exactly happened before, during and after the impact - and what that could mean for protecting the earth. The data during the impact will be collected by the small cube satellite LICIACube, a contribution of the Italian space agency ASI to the mission. In 2024, the Esa mission "Hera" should start for even more detailed investigation, which Queen guitarist and astronomer Brian May explains in more detail:
First, however, "Dart" does the preparatory work. It is a "test mission," emphasizes Nasa manager Andrea Riley. "Even if we don't score, we'll still be able to collect a lot of data. That's why we're testing. We want to do it now and not when there's a real problem."
