Scientists have increased the likelihood of a collision of the Earth with the potentially dangerous asteroid Bennu. The results of a recent mission to him showed that a number of factors could not be taken into account before.
Potentially dangerous near-Earth asteroid Bennu may collide with the Earth before 2300 with a probability of 1/1750, and this probability turned out to be higher than previously thought. This is the conclusion reached by American scientists who made the most accurate calculations of the orbit of this cosmic body.
Asteroid Bennu, 560 meters in diameter, has attracted exceptional attention from astronomers since its discovery in 1999. It is part of the Apollo group – near-Earth asteroids, whose orbits cross the Earth from the outside, and is a “pile of rubble”, as astronomers call bodies, which are not monoliths, but a conglomeration of debris held by mutual attraction.
Since the discovery, astronomers have closely studied the properties and orbital characteristics of the asteroid using telescopes, and today NASA considers it one of the two most dangerous in the solar system, along with the 1950 DA asteroid.
In 2016, NASA launched the OSIRIS-REx mission to an asteroid in order to study in detail and return rock samples from the body to Earth. The device arrived at him in 2018, spent two years in orbit of the asteroid, after which it took samples from the surface and sent them to Earth.
But besides this, scientists were able to investigate the parameters of the asteroid, which determine its probability of collision with the Earth in the future.
To refine its trajectory over the next two centuries, scientists evaluated such insignificant factors as the pressure of sunlight on the asteroid, the gravitational pull from more than three hundred other asteroids, and the influence of interplanetary dust. One of the key factors is the so-called Yarkovsky effect, which arises from the influence of solar radiation photons on cosmic bodies.
Scientists were even able to assess the impulse that the OSIRIS-REx device itself gave the asteroid at the time of approach and landing. As expected, this maneuver had an almost subtle effect on the asteroid.
All this now allows scientists to consider Bennu the most studied asteroid in the solar system. “The OSIRIS-REx mission gave us extremely accurate data about Bennu’s position and movement in space, which has not been done with any asteroid before,” said Lindley Johnson of NASA’s Asteroid Defense Division.
In an article published in the journal Icarus, scientists led by David Farnocia of NASA’s Jet Propulsion Laboratory used new data and computer simulations to narrow down the uncertainties in the asteroid’s orbit, estimating the probability of its collision with Earth before 2300 as 1/1750 (0.057%).
and named the date September 24, 2182 as the most dangerous from this point of view (the probability of a collision is 1/2700).
“Bennu has become the most studied asteroid in the solar system,” notes co-author Dante Loretta. – Now we know where he will be in a hundred years with an accuracy of meters. No other object in the solar system has such an accurate solution to its orbit, not even the Earth! ”
The new data helped to better predict the evolution of the body’s orbit over time and whether the asteroid will fall into special points in space, the so-called. keyholes during the 2135 approach to Earth, which will determine its possible collision with the Earth in the future.
Despite a slight increase in collision risks, scientists are in no hurry to sound the alarm – the risk remains below 0.1%. But, although a collision with it does not compare with the impact of an asteroid that killed the dinosaurs, it can still cause a catastrophe on a regional scale.
Previous calculations showed that a collision of the Earth with Bennu would be equivalent to an explosion of 1.1 billion tons of TNT, which is a million times more powerful than last year’s explosion in the port of Beirut.