The scientists who conducted the study warn: it’s only a matter of time before a devastating asteroid – as many as 28 of them – will hit the Earth

Humanity has so far managed to avoid a catastrophe of this magnitude, but it is only a matter of time before the asteroid that threatens the collapse of civilization will turn towards us. Little by little, technologies are being developed to prevent a catastrophic impact, but this requires spotting a dangerous asteroid in time and place.

Asteroids, even large ones, are abundant in the solar system, so it is important to know which ones are potentially dangerous and worth monitoring. With information about an asteroid’s trajectory, we can calculate its orbit and try to predict if—and when—it will collide with Earth. But here comes the problem: predictions are only reliable about a hundred years into the future.

Over longer timescales, asteroid orbits become chaotic—even very small errors in the initial conditions lead to huge changes in predictions. And the properties important to the model are really diverse – not only the current position and speed of the asteroid, but also its size and shape, which depend on the heat received from the Sun, and the movement of the planets, which perturbs the orbit.

In a new study, scientists attempt to circumvent these obstacles by studying asteroid collisions with Earth probabilistically. For each of the 157 asteroids larger than a kilometer with an orbit that passes less than 0.05 AU (the distance from the Earth to the Sun) from the Earth’s orbit, they calculated the expected motion over the next thousand years.

This was done many times, varying the initial parameters within the limits of error. This allowed them to determine which asteroids could approach Earth closer than the Moon’s orbit and estimate the probability of such an approach.

28 such asteroids have been discovered.

The most dangerous appears to be asteroid 7482 (it doesn’t have a name), which will spend most of its time in very close orbit over the next millennium. It is difficult to say how close it will be to the Earth itself, but it is definitely worth watching.

Another exceptional asteroid is 143651, whose orbit turned out to be very chaotic, unpredictable over a period of more than a few decades. These results will help to choose which asteroids to pay the most attention to when refining the parameters of their orbits.