It only happens once a decade. Saturday March 25, at 8:49 p.m. French time, a large asteroid will graze the Earth. But don’t panic: the European Space Agency (ESA) has announced that the event is safe for our planet. Instead, the asteroid will serve as a planetary defense training exercise. Named 2023 DZ2, the asteroid measures between 40 and 70 meters in diameter, large enough to wipe out a large city if it were to hit the surface of the blue planet.

But there is no need to worry, reassures Richard Moissl, head of ESA’s planetary defense office. Even if it passes at a speed of 28,000 km/h, it will not approach the Earth closer than 175,000 kilometers.

2023 DZ2 was first spotted on February 27 by an observatory in La Palma, one of Spain’s Canary Islands. And it is therefore its rarity that interests scientists. The goal is to discover everything it is possible to learn about an asteroid in just one week, says Richard Moissl. This will serve as a practice for how the network will “react to such a threat” in the future, he added. 2023 DZ2 will thus be analyzed using a series of instruments, such as spectrometers and radars.

This is obviously not the first time that an asteroid has approached Earth. In early March, astronomers had estimated a 1 in 432 chance that 2023 DW, another similarly sized asteroid, would collide with Earth. Since then, after more precise calculations, any risk has been ruled out. But if, one day, such an object were really heading towards us, the Earth would not be defenseless. Last year, NASA’s Dart spacecraft deliberately crashed into the asteroid Dimorphos, about 11 million kilometers from Earth, and managed to deflect its course.