ESA expert: The risk from asteroids remains low, but planetary defense requires preparation

Patrick Michel, a renowned asteroid expert and one of the central figures at the European Space Agency (ESA), has explained the risk posed by a possible asteroid collision with Earth, as well as international efforts on planetary defense within the framework of the European Hera mission.

He estimates that, at the moment, there is no known asteroid that poses a threat to Earth in the short or medium term. According to him, orbital calculations extend roughly a century into the future and, so far, have not revealed any imminent collision risk.

Nevertheless, Michel emphasizes that many smaller asteroids have still not been identified, so the risk in the future cannot be completely ruled out.

According to him, scientists have discovered nearly all asteroids with a diameter of more than 1 kilometer, which could cause global catastrophes, and none of them is considered a known threat.

The main challenge, however, is linked to the detection of celestial bodies over 140 meters in size, capable of causing damage on a regional scale. Michel says that so far only about 40% of them have been identified, while the rest remain unknown.

Planetary defense, meanwhile, has entered a new stage after NASA’s historic DART test, which in 2022 collided with an asteroid to alter its orbit.

On the other hand, ESA’s Hera mission, launched in 2024, will examine the consequences of that impact in order to better understand how effective the kinetic deflection method is. This mission will analyze the asteroid’s structure and the crater formed, also using CubeSat microsatellites for detailed measurements.

According to Michel, one of the greatest difficulties is not related only to technology, but also to international coordination. He stresses that, as things stand today, there is no unified global protocol for a rapid response in the event of a real threat.

He also recalls that the United Nations has set up working groups to coordinate the global response, but fundamental issues related to decision-making, evacuations and the use of technology in emergency scenarios still remain unresolved.

Michel stresses that, although this risk remains low compared with other natural threats, preparation is vital, because a possible collision, however rare, could have major consequences.

According to him, the technology for deflecting asteroids has already passed testing, but creating global response systems requires time and long-term cooperation.

“Planetary defense is not fear, but preparation,” Michel emphasizes, adding that humanity must be ready long before such a threat becomes reality.