It is believed that it arose as a result of the collision of the Earth’s natural satellite with another planet, but there are questions about this version. Now scientists have proposed considering the possible scenario of capture of the Moon by the Earth’s gravity from a flying binary system.

One of the most important scientific results of the “Apollo” program was everything that planetary scientists learned and continue to recognize during the study of lunar samples. Shortly after these were obtained, it became apparent that lunar material was generally very similar to terrestrial matter, both in composition and age. This ensured the success of the most popular hypothesis until recently (the giant impact hypothesis). It says the Moon formed from terrestrial material thrown into space by Earth’s collision with an unknown Mars-sized planet. It was named after Theia, the legendary mother of the goddess Selena.

But in recent years, it has become clear that this hypothesis does not fit well with much data about the Moon, including the Moon’s peculiar orbit, which has been a long-established fact.

The “native” natural satellite of the planet, that is, the one that arose with it, usually rotates evenly or at least “more or less” in the equatorial plane. A canonical example is the Jupiter system: the largest Galilean moons are built in a “disciplined” way, in “musical” harmony. And this contrasts with the “character” of the Moon: the angle of inclination of its orbit to the Earth’s equator varies from 18 to 28 degrees.

At the same time, the plane of the lunar orbit deviates relative to the ecliptic by no more than five degrees. We will remind you that the plane of the ecliptic is the plane in which the Earth revolves around the Sun. It tries to stay above the equator of the luminary along with other planets. Therefore, the Moon’s orbit clearly reveals its “tendency” towards the Sun and raises relevant questions.

Recently, astrophysicists from the University of Pennsylvania (USA) have developed a scenario in which, in the case of the Moon’s origin, it could occur not as a result of a collision between two planets, but as a result of its capture from a double planet. A system of small objects.

According to this version, the Moon once had a “partner” from Charon with a mass similar to Pluto. If such a pair turns out to be close enough to the Earth and at the same time not flying too fast, the planet’s gravity will slowly capture one of the bodies and push the other away.

Scientists modeled this process based on mathematical calculations and discovered that in this case the Moon could have a longer orbit but would later become circular. At the same time, the Moon must gradually move away (which is actually happening) and eventually becomes so far away from the Earth that the Sun begins to compete with the planet for its “attention.”

Calculations showed that, in principle, the Earth could “instantly stop” something larger than the type of Mercury or even Mars, but the orbit of such a body would be unstable. The Moon has the best dimensions in this sense.

In his last article for Planetary Science Journal Astrophysicists emphasized that they have not definitively and irrevocably confirmed the accuracy of their assumptions, but they are sure that this version needs further development. They gave Neptune’s moon Triton as an example. One in ten celestial objects are thought to be captured from the Kuiper Belt, where they are suspected of flying with a companion.

The new study is almost certain to raise objections among planetary scientists. The fact is that the ratio of isotopes of various elements is a unique “signature” of each celestial body. The situation is the same on the Moon and on the Earth: the ratio of hydrogen isotopes and many other elements on them coincides and at the same time differs sharply from the rest of the bodies of the Solar System. This indicates the common origin of their substances.