While the United States and China do not collaborate in the space domain, coordination on an international scale is not out of reach, according to the specialists interviewed by franceinfo.
Hip hip hip, Hera! The European Hera mission is scheduled to take off on Monday October 7, conditions permitting, from the Cape Canaveral base in Florida (United States), aboard a SpaceX Falcon 9 rocket. This mission works in conjunction with that of NASA, Dart, which succeeded in deflecting an asteroid from its orbit in September 2022, 11 million kilometers from Earth. The two programs were designed to work in pairs: Dart can be considered as the actor and Hera as the inspector who comes to observe and better understand what happened beforehand.
This tandem is part of what is called “planetary defense”, that is to say the capacity to protect the Earth against a celestial body (such as an asteroid or a comet) likely to strike it. This type of threat, popularized by films like Armageddon (1998), Deep impact (1998) and more recently Don’t look up (2021), are not simply science fiction.
The time scale of a possible cataclysm remains vast since no danger has been detected for the coming century. But the probability exists, explains Patrick Michel, research director at the CNRS at the Côte d’Azur Observatory, and scientific manager of the Hera mission. “An object one kilometer in diameter falls on average every 500,000 years on Earth. This is the threshold for catastrophe on a global scalehe explains. An object 140 meters in diameter, which is the threshold for disaster on a regional scale, is on average every 20,000 years.”
Large objects, at least 1 km in diameter, have almost all been identified. But only 40% of those around 140 meters in diameter are, specifies Patrick Michel. Faced with these figures, NASA, the European Space Agency (ESA) and other partners have therefore begun to develop the first elements of the procedure to follow in the event of an asteroid threat, from detection to intervention. on this big threatening stone. In these shots, the idea that predominates is not the one shown in the cinema: detonating it would only transform it into an even more dangerous cluster bomb. Scientists agree that the best option is to deflect it, and prepare for it as early as possible.
For its part, China (whose space program remains ambitious) has also announced that it is working on a plan to protect the planet. It wants to hit an object 30 meters in diameter in 2030 and also send a pair of devices to accomplish this task and observe it. This is not surprising, because Chinese President Xi Jinping intends to put his country at the forefront in the space sector by 2030. In this tense context, Beijing and Washington are not collaborating in this area. “The Chinese have never been invited to the International Space Station For example”recalls to franceinfo the Belgian astrophysicist Emmanuel Jehin, specialist in the study of small bodies in the solar system. “This is even less the case now, with China and Russia working together to set up a base on the Moon, and create a new space station.”
Developing several programs to anticipate a critical situation is not necessarily problematic. It is above all a question of ensuring that all the actors push in the same direction, assure the scientists interviewed. But, concretely, what would happen if an asteroid 150 meters in diameter, with a certain risk of impact on Earth, was identified? Could the great powers bury their differences to limit the damage and save lives? A path is possible, if it is traced by several people, says Patrick Michel. “It would be complicated to get a bilateral mission with the United States and China, but as soon as several countries work multilaterally, it seems to pose fewer problems.”
International cooperation has also been taking shape under the aegis of the UN since 2014, with a group dedicated to planetary defense, the Space Mission Planning Advisory Group (SMPAG). This body, which seeks to put in place a coordinated international response, brings together around fifteen space agencies, including that of the United States (NASA), Europe (ESA), Japan (Jaxa) but also China (CNSA) and Russia (Roscosmos).
In fact, “the Chinese are not very present” during meetings, notes Patrick Michel, who appears rather optimistic. Seeing the United States and China around the same table must be interpreted as an encouraging signal, also believes Franceinfo Jean-Claude Worms, executive director of Cospar, the international committee for space research. A committee which, according to him, would find “the role given to it during its creation in 1958, an open bridge” for cooperation in space between the Soviets and the Americans.
“If we are talking about an event capable of destroying cities or entire regions of the planet, I think that international coordination would be put in place between the great powers.”
Jean-Claude Worms, executive director of Cosparat franceinfo
And this, even if many practical details remain to be decided, according to specialists. A planetary defense mission would thus include a “strong technological dimension”, an area in which exchanges between Americans and Chinese are currently unthinkable.
Faced with the threat of a devastating asteroid, dizzying questions also arise. At least, in the current state of thinking. “If an object is coming, and we know that it is impossible to completely deflect it from the Earth’s path, but we can make it fall in a less populated region than expected, where should we make it fall? How will countries agree to target the Gobi Desert rather than the Pacific Ocean, for example? It’s not that simple”notes Jean-Claude Worms.
A coordinated international response could suggest common responsibility. However, “every man for himself” remains. Patrick Michel explains that there is a section within the UN special group in charge of legal affairs. Its members are considering legislation so that the agency commissioned is legally protected in the event of failure. “He who throws [la sonde] don’t want to be the one who failed”observes the scientific manager of the Hera mission.