Earth has its own "air defense system" that could save humanity from "planet killer" asteroids
The Earth likely has a natural defense system that allows it to escape potential collisions with planet-killing asteroids on its own. We are talking about intense gravitational forces that can tear apart large asteroids that come too close.
This is stated in a study published on the arXiv preprint site. Subsequently, the work of scientists will also appear in the peer-reviewed journal The Astrophysical Journal Letters.
It is known that there is a gravitational interaction between bodies in space. If we are talking about a huge planet like the Earth and an asteroid that is much smaller than it, the so-called tidal forces will also arise between them (the name originated from astronomers' explanations of the interaction between our planet and the Moon). Therefore, if the Earth's gravitational pull is much stronger, the asteroid may undergo tidal destruction while still in space.
This is not just a theory that exists on paper. In 1994, Earth-based astronomers saw with their own eyes the debris of Comet Shoemaker-Levy 9, which was torn apart by Jupiter's tidal forces and subsequently thrown at the gas giant.
However, scientists had no evidence of the ability of the Earth (or other similar planets) to undergo such tidal destruction.
Therefore, Mikael Granvik, a planetary scientist at Luleå University of Technology in Sweden, who is the first author of the new study, and his team have been looking for such gravitationally torn-apart near-Earth asteroids.
After years of unsuccessful searching, he concluded that any fragments formed in this way would "blend into the background so quickly" that it would be impossible to identify them.
In 2016, continuing his research, he helped create a model that calculated the trajectories of asteroids of different sizes to determine their number at different distances from the Sun. The data was then compared to seven years of asteroid observations collected by the Catalina Sky Survey, a NASA-funded program.
This comparison revealed many missed asteroids that were quite small and moving in a roughly circular pattern around the Sun, more or less in the same plane as the orbits of the Earth and Venus. At first, these asteroids were of no use to Granvik's research, but later he realized that they might be fragments of larger asteroids, destroyed by tidal waves.
To test this idea, the scientists considered a scenario in which asteroids that collided with rocky planets lost 50% to 90% of their mass, generating debris flows. This model explained the existence of these small asteroids by suggesting that they were created by tidal disturbances.
Additional simulations showed that such fragments of large asteroids could have circled the Sun for millions of years until they fell on it or another planet, or were expelled from the solar system.
Granvik also explained that although such tidal forces tear asteroids into smaller pieces rather than destroy them completely, these pieces would not pose a global threat to humanity as these fragments would be less than 1 kilometer in diameter.
However, they "increase the likelihood of events of the level of the Tunguska and Chelyabinsk cataclysms," the two largest asteroid impacts in recent history.
Earlier, OBOZ.UA reported that an asteroid, which was considered lost for 16 years, is heading towards the Earth.