Over centuries of astronomy and space exploration, scientists have discovered hundreds of moons in our solar system, giving Jupiter a record 92 moons, surpassing Saturn’s 83 confirmed moons.
Although scientists have found that asteroids can also have small companion moons, some planets in the solar system do not have such satellites, such as Mercury and Venus.
For the Earth, this is very clear in relation to the Moon, as we have known only one natural satellite of the planet for millennia.
We may have had more moons in the distant past and we may catch more in the future, but right now we only have one.
Gábor Horváth, an astronomer at Loránd Otvös University in Hungary, said that the “moon” holds the title of Earth’s only fixed and permanent moon. But this is not the only object that is pulled into Earth’s orbit, as there is a group of near-Earth objects and dust clouds that are also stuck in Earth’s gravity. These companion objects are often temporary and technically qualify as mini-satellites, quasi-satellites, or trojan satellites.
So the question of how many moons the Earth has is more complicated than we think.
Back in the early days of the Earth, about 4.5 billion years ago, there was no Moon on our planet. Then, about 4.4 billion years ago, a Mars-sized protoplanet called Theia crashed into Earth. Then he threw large chunks of the earth’s crust into space.
According to a study published in 2022 in The Astrophysical Journal Letters, rock fragments coalesced, possibly within hours, to form the moon.
Other “moons” a few feet in diameter were mostly temporary, trapped by Earth’s gravity for short periods of time before flying back into space.
In 2006, an asteroid up to 20 feet (6 meters) in diameter, named 2006 RH120, a space rock that remained in orbit around Earth for 18 months, became the first long-term observation of an asteroid in Earth’s orbit.
There was also 2020 CD3, an 11.5-foot-wide (3.5 m) space rock that left Earth’s orbit in March 2020 after spending three years as a small second moon.
In 2020, scientists also discovered SO 2020, a young satellite that returned to space in early 2021. However, it turned out that SO 2020 was not a natural satellite, but the remnants of a 1960s booster.
For 13 hours in 2015, scientists thought they had found a new temporary moon orbiting the Earth. But they quickly realize their mistake when the “moon” is revealed to be the European Space Agency’s Gaia space telescope.
In addition to the moons that come and go from Earth’s orbit, there are space objects that NASA refers to as Trojans, such as the asteroid 3753 Kruitn.
These space rocks revolve around the Sun in such a similar way to the Earth that they stick to our planet throughout its 365-day orbit.
Scientists have previously reported on a Kamo’oalev quasi-moon that has been chasing the planet for almost a century, orbiting the Earth for many years, and likely to keep moving for centuries. And NASA announced that although this asteroid is too far from Earth to be a new moon, it is stable enough in its orbit to be considered a “close satellite of the Earth” or a new moon a “half moon.”
Some space objects, such as asteroid 2010 TK7, are nicknamed “Moon” because they are captured by the unique gravity of the Sun-Earth or Earth-Moon systems. According to NASA, the gravity of two large objects creates regions of gravitational force called Lagrange points that hold smaller objects in place at fixed gravity points in space.
Horvath said: “In parallel with the formation of the solid Moon and the stability of its orbit around the Earth, the Lagrange points L4 and L5 also arose, which began to collect and trap dust particles between the planets. Some astronomers call these clouds Trojan moons. They are also called Kordelewski clouds, after the Polish astronomer who first reported it in the 1960s. At first, many scientists were unconvinced, but research by astronomers like Horvath has since confirmed that dust clouds accumulate at these Lagrangian points. .”
However, these Trojan moons will never form a harder moon because dust cannot bind, stick, or clump together, Horvath said, explaining that while the Lagrange points remain constant, matter in them is dynamic, constantly moving in and out of the dust. clouds.
Source: Living Science
