Modern astronomers are sure that 100 million years ago there could have been two or three, and maybe even a dozen. Everything changed the moment the hypothetical planet Theia swept through the solar system. The wandering celestial body scattered the rest of the planets in new orbits, collided with Mars and crashed into the Earth. The real satellites of our planet were thrown away, and as a result of the impact, the Moon was born.
This is the picture that the most reliable version of the development of events, reconstructed using computer modeling, paints. It was conducted by American astronomers from NASA and the Carnegie Institute.
The model showed that if the Earth had satellites, then after meeting with Theia, they left their orbits and ended up among objects known as Trojan asteroids. This cluster of small celestial bodies is located in the vicinity of Jupiter, and the asteroids that make up it are named after the heroes of the Trojan War - both the defenders of the city and representatives of the Achaean (Greek) army.
The most likely new location of the former satellites of the Earth is the fourth point of Lagrange in orbit of Jupiter, where the heroes of the besieging army - Achilles, Odysseus, Agamemnon, Ajax and Menelaus - gathered. Their sizes are small - only 100 to 200 kilometers in diameter, but this is how astronomers imagine the ancient moons of the Earth.
In addition, the remnants of the building material of the destroyed moons could have accumulated at the Lagrange points in near-earth orbit - positions where the gravitational fields of the Earth and the Sun balance each other.
However, the collision with Theia could not but affect the orbit of the Earth itself. With a gradual change in the trajectory of our planet, the Lagrange points began to shift. The fragments of the earth's moons were again under the influence of gravity, which either threw them further from the Earth or destroyed them.
An alternative computer simulation, carried out by Canadian astronomer Mathieu Cuke, has shown that even a relatively small asteroid formed after a collision, whose diameter does not exceed ten kilometers, can maintain a stable position in the solar system for a long time. Moreover, the larger the celestial body, the longer it stays in one place.
Cueck says small moons can remain in stationary positions for billions of years: “From the ground, they can look like planets like Venus or Jupiter. This applies to both brightness and visible size. Cuke is convinced that the discovery of such planetoids is only a matter of time. In the meantime, astronomers cannot even name the exact number of dwarf planets in the solar system and their location.
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Theia's "walk" through our system has so drastically changed the appearance of the planets and their orbits that the study of the consequences of a space voyage will take astronomers more than a dozen years. Although for this it would be worthwhile to initially deal with the main question - how true is the theory of the "stray planet" itself, because direct evidence of Theia's existence has not yet been found.
PAVEL URUSHEV