Scientists at the University of Nevada, Las Vegas, have hypothesized that in the early periods of the Earth-Moon system’s existence, it could have had small companions in polar orbits.
Today, the Moon orbits the Earth at a distance of approximately 384,600 km, which is 30 times the diameter of our planet. However, this distance is constantly increasing — the Moon is moving away from the Earth at a rate of about 3.8 cm per year.
The researchers note that the Moon was formed almost 4.5 billion years ago, probably as a result of the Earth’s collision with a Mars-sized object. After this catastrophic event, the Moon was formed at a distance of only 19,135 km from the Earth, which is about 1.5 times the diameter of our planet.
Steven Lepp, co-author of the study, explains:
«In the initial stages of the formation of the solar system, there were many more small bodies and debris than today».
Most of the debris that formed during the formation of the Moon probably collided with the Moon or the Earth, or was thrown away from both. However, some of them may have orbited the Earth and the Moon in what are known as circular orbits.
The researchers found that the Earth-Moon system could have had a satellite or disk in a polar orbit — that is, around the poles of the Earth and Moon, not the equator. Such orbits were stable from the moment the Moon formed until the distance between the Earth and the Moon reached 7.5 Earth diameters.
Although today the Moon’s orbit is inclined by 5 degrees relative to the Earth’s orbit around the Sun, previous studies have suggested that during formation this inclination was at least 10 degrees. The presence of satellites in polar orbits could have influenced the evolution of the Earth-Moon system and explained these mysterious aspects.
Lepp concludes that these findings open up the possibility of stable polar moons forming in exoplanetary systems, which could have observable implications for future research.
The results of the study have been accepted for publication in the journal Astrophysical Journal.
As a reminder, researchers from China found evidence of the presence of water in the lunar soil samples collected by the Chang’e-5 mission, which opens up new perspectives in the study of the Earth’s natural satellite.
Source: Space
Spelling error report
The following text will be sent to our editors: