Detected on February 26, 2022, this asteroid could crash into Earth in 2046. But the chances of that happening are extremely low, according to NASA.
The story seems to come out of the disaster movie Armageddon. However, NASA has announced on Twitter, Tuesday, March 7, having discovered and placed under surveillance nine days earlier an asteroid called 2023 DW. And according to calculations by the US space agency, this celestial object with a diameter of about 50 meters could hit our planet on February 14, 2046, for a unique Valentine’s Day. Collision probabilities, possible impact zone, means of surveillance… Franceinfo takes stock of this asteroid alert.
1 in 625 chance of crashing into Earth
The chances that 2023 DW will hit our planet are infinitesimal, reassures NASA, even if it will still take “several weeks of data collection to reduce uncertainties” about this asteroid. “As soon as we discover an object of this type, we predict its trajectory for the next century (…) and in the majority of cases, we eliminate the risk of collision very quickly”, has explained to CNN Davide Farnocchia, engineer of the space agency. “But [pour cet astéroïde] we can’t do it yet, we need more data.”
According to the Planetary Defense Coordination Office, a NASA service dedicated to monitoring and protecting the Earth against near-Earth objects (like asteroids), the probability of a 2023 DW impact is approximately 0. .16% – i.e. one chance in 625. “I prefer to put it another way: there is a 99.8% chance that this object will not reach the Earth”summarized Davide Farnocchia at the microphone of CNN.
First reassuring estimates
Also according to NASA, this asteroid is currently 0.13 astronomical units from Earth (or approximately 19.4 million kilometers) and travels through space at a speed of 24.63 kilometers per second… or more than 88 000 km/h on the odometer. But don’t panic, repeats the space agency, which offers real-time monitoring of asteroids on its site (in English). According to the latest estimates, 2023 DW is expected to pass more than 1.8 million kilometers from Earth on February 14, 2046 – a distance five times greater than the distance between our planet and the Moon.
Could this asteroid cause significant damage, if it were to crash into Earth? “Its size is interesting, because it’s roughly the size of the asteroid that would have disintegrated above Tongouska. [en 1908, dans le centre de la Russie]which had nevertheless caused the destruction of hundreds of square kilometers of forests”underlines to franceinfo the physicist Richard Moissl, specialist in asteroids at the European Space Agency (ESA).
As Richard Moissl reminds us, the dangerousness of an asteroid depends on its size, but also on its point of impact, on land or at sea, far or close to inhabited areas. “Its composition is also very important, argues the physicist. A ferrous asteroid can be more resistant to the atmosphere and cause a powerful impact, as happened in Meteor Crater, Arizona [Etats-Unis] tens of thousands of years ago.”
The asteroid will be monitored for a few more weeks
The various space agencies regularly detect near-Earth objects. “Our list currently has 31,000, explains Richard Moissl, with approximately 1,450 asteroids posing a risk of collision with Earth.” But pay attention to the definition of this “risk” : despite its extremely low probability of impact, 2023 DW still ranks first in this “risk list” from ESA (document in English). “It is the only one to be ranked 1 out of 10 on the Turin scale [du nom du baromètre utilisé pour catégoriser les risques d’impacts des astéroïdes ou des comètes]”specifies the physicist, explaining that this object is neither to be followed, nor dangerous according to this classification.
“We remain very calm, assures Richard Moissl, the object will be observable in the coming months and we will have new measurements within two to three weeks, in order to recalculate the risk. If scientists had had the slightest concern, “we would have already informed the International Asteroid Warning Network and the group of space agencies under the aegis of the UN, which would have taken the appropriate measures”details the physicist.
Among these measures, we find the possibility of deflecting an asteroid from its trajectory, as was done for the first time in history last September, during the Dart mission. A NASA “kamikaze” spacecraft then struck and changed the course of the asteroid Dimorphos, 160 meters wide, some 11 million kilometers from Earth.