Like the Gauls of Asterix, we must fear that the sky will fall on our heads. But if we have always thought that it would collapse in the form of asteroids, a team of astronomers from the University of Buckingham and the Armagh Observatory have warned that the real danger comes from some peculiar objects located in the outer Solar System and that they take observing for the last two decades.
These giant objects are called Centaurs , as they appear to be a mixture of asteroids and comets (like the mythological half-man, half-horse centaur), they move in unstable trajectories as they cross the orbits of Jupiter, Saturn, Uranus and Neptune. Obviously, the gravitational pulls they are subjected to by these gas giants cause their orbits to alter and, from time to time, line the path to Earth.
The Centaurs have a typical size of 50 to 100 km and a single body has more mass than the collection of all the asteroids that cross the orbit of the Earth discovered to date. According to the calculations made by this team of astronomers, one of these Centaurs heads towards Earth once every 40,000-100,000 years, although the problem is not that it is going to collide with us; it is something much worse. When it is close to the Sun it disintegrates, creating a cloud of dust and solid debris and flooding the inner Solar System with debris that makes the impact of some of them with our planet inevitable.
