Chemical and physical analysis over the decades has shown that there is a similarity between the composition of the rocks of the Moon and Earth, and it turns out that they are rich in calcium and basalt, dating back to around 60 million years after the formation of solar energy. system.
This prompted scientists to suggest that the origin of the Moon was terrestrial, and in 1984 the currently dominant theory emerged that the Moon formed after a Mars-sized planet (called Theia) entered collided with Earth billions of years ago, causing some of the matter from this collision to separate to form what we now know to be the Moon.
But, according to researchers at Pennsylvania State University in… study According to a new study published in the Planetary Science Journal, the above is incorrect and the Moon was captured at a time when it was passing near Earth in ancient times.
For the sake of the analogy, imagine that you are catching a ball that passes quickly by you, but instead of your hands, the Earth has a gravitational force that can catch objects that pass by it. ‘She.
Here’s a short video from NASA explaining the prevailing theory about the origin of the Moon:
Capture exchange theory
The researchers explain in the new study that there are questions that conflict with the fact that the Moon was created by collision, fragmentation, and then reconstruction, because if that had happened, the Moon would have must have orbited above the planet’s equator. but it runs on a different level. Rather, it appears that the Moon is more in harmony in its orbit with the Earth’s equator.
While the new theory adopted by this team, called “exchange capture theory”, explains that Earth’s gravity captured the moon when it was in a binary system (i.e. orbiting around ‘another small body), then separated them from each other with gravitational forces, which led to the moon being captured and rotated to its current level.
Calculations carried out by the research team showed that the aforementioned separation process corresponds to the current orbit of the Moon and its deviation from what is expected of it, and also corresponds to the influence gravitational force of the Sun on the Moon.
The study shows that there is evidence that this type of capture occurred elsewhere in the solar system, where scientists believe that Triton, for example, which is the largest of Neptune’s moons, was pulled toward Neptune from the Kuiper belt.
Triton orbits Neptune in a retrograde orbit, moving in the opposite direction to the planet’s rotation, and its orbit is significantly tilted relative to Neptune’s equator (at an angle of 67 degrees).
But Triton’s situation is different from that of the Moon, because the Moon actually rotates in an inclined orbit, but at an angle of only 5 degrees. In this context, more observational evidence and studies are still needed to confirm the new hypothesis.