Discovered last Saturday, the asteroid named 2017 AG13 passed close to Earth on January 9 at 7:47 a.m. ET. A lightning passage for this piece of rock that no one had seen coming and whose diameter thus oscillated between 25 and 35 meters for an estimated speed of sixteen kilometers per second.
Researchers have long expressed concern about threats from potentially dangerous asteroids or meteors. Last month, the White House published a detailed plan entitled « National Near-Earth Object Preparedness Strategy » aimed at preparing the world against this type of unpredictable threat. And 2017 AG13 was, unpredictably. Spotted only last Saturday, the asteroid passed quite close to our position at a distance halfway between our planet and the Moon, about 190,000 kilometers away, as it crossed the orbits of Earth and Venus.
With a diameter oscillating between 25 and 35 meters and moving at an estimated speed of 16 kilometers per second, 2017 AG13 would nevertheless not have done (too much) damage. In any case, this is what the emergency impact simulations carried out by the director of the Institute of Planetary Sciences, Mark Sykes, suggest. The measurements indeed predicted the explosion of the piece of rock when it entered the atmosphere: “ The explosion would have released 700 kilotons of energy, dozens of times more powerful than the explosion of the atomic bomb on Hiroshima “, explains the researcher. » This explosion would nevertheless have taken place at about fifteen kilometers altitude and would not have impacted the ground. « .
2017 AG13 should therefore not linger on the Earth, but that does not prevent it from spilling a lot of ink since the beginning of the week. And for a fairly simple reason: no one saw it coming. Remember that millions of asteroids circulate permanently in the Solar System. However, according to the Planetary Society, we have discovered only 60% of the short-period asteroids and comets near Earth (with orbital periods of less than 200 years) whose diameters are estimated at 1.5 kilometers or more. The good news is that potentially dangerous bodies only have a 0.01% chance of impacting Earth within the next hundred years.