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A Kamikaze spacecraft will crash into an asteroid on Tuesday night. A first test for emergencies.
It will be a historic moment, the astronomers from Nasa, Esa and other space organizations involved agree: On the night of Tuesday, September 27 at 01:14 Swiss time, the DART space probe will crash into an asteroid. More specifically, in the 160-meter-wide Dimorphos, which orbits a larger asteroid called Didymos.
The probe will be destroyed in the process, but that’s beside the point. Importantly, the impact will deflect the asteroid slightly from its current orbit.
“It’s a rather small spacecraft crashing into a much larger asteroid. The impact will not be gigantic,” says Nancy Chabot, who coordinates the mission, in a media briefing. The deviation from today’s orbit will therefore be rather small. But enough for a first test of this technology.
DART stands for Double Asteroid Redirection Test Mission and is intended to show whether, in an emergency, an asteroid or comet that is racing towards Earth could be warded off in this way.
Over 95 percent of the very largest asteroids have already been found and none are currently a threat to Earth.
Millions upon millions of asteroids orbit in our solar system. Most of these boulders are only a few meters in size, but there are also huge ones with a diameter of 1000 kilometers. They orbit the sun like planets – some of them cross the orbit of the earth and can come dangerously close to it.
Researchers around the world are searching for and monitoring the near-Earth asteroids. “More than 95 percent of the very largest objects have already been found and none is currently a threat to Earth,” says astrophysicist Martin Jutzi from the University of Bern, who is involved in the DART mission.
Asteroids between 100 and 200 meters are more dangerous. Only around 50 percent are known here so far, “but this area is much more important because these objects hit the earth much more frequently than the very large ones”.
course of the mission
DART has been on the road since November 2021. After a journey of more than 11 million kilometers, the biggest challenge awaits the Kamikaze probe on Tuesday night: hitting the small asteroid at all at a speed of around 22,000 kilometers per hour.
The probe navigates autonomously. Only an hour before impact will she be able to distinguish the asteroid moon from the large asteroid Didymos. Then she must independently fire the thrusters and set the final course to her target. Thanks to the camera images, scientists and space fans around the world can follow the crash live.
Three minutes after the impact, the companion satellite LICIACube will photograph the impact in the fly-by. For the time being, nothing more than a large cloud of dust will be visible. But these are the images that the scientists are eagerly awaiting, because they show that the maneuver worked. The images will reach Earth over the next 24 hours. In the weeks after the crash, telescopes on the ground will observe whether the hoped-for shift in orbit has taken place.
For more detailed analyses, ESA will launch the follow-up mission HERA in October 2024. The probe and its companion satellites will take pictures of the crater and determine the size and composition of the asteroid.
With this information, models by scientists such as Martin Jutzi and asteroid defense can be further improved. Because purely statistically, the emergency will come at some point.