Earth is about to get a temporarily second moon, starting next week, as a new mini-moon will orbit our planet.
According to scientists, an asteroid will revolve around Earth for two months before it breaks free from the planet’s gravity and continues its journey through the solar system.
Spotting the Mini-moon
Researchers at the Asteroid Terrestrial-impact Last Alert System, an asteroid monitoring system funded by NASA, discovered a small asteroid in August using a South Africa-based observatory. They labelled it 2024 PT5.
According to their study, published in Research Notes of the AAs, the 2024 PT5 belongs to the Arjuna asteroid belt, which orbits the sun. Scientists tracked the 2024 PT5’s orbit for 21 days to determine its paths.
They calculated that Earth’s gravitational pull will draw the asteroid towards it. As a result, the 2024 PT5 will orbit our planet for 56.6 days, from September 29 to November 25, 2024.
Phenomenon Explanation
According to NASA, Near-Earth Objects (NEOs) are comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth’s neighborhood.
Hence, Earth’s gravity will draw the 2024 PT5 into its orbit. Meanwhile, the asteroid will have negative geocentric energy, preventing it from escaping the planet’s gravitational pull. It will revolve around Earth in a horseshoe orbit, before returning back to its orbit around the sun.
“Earth can regularly capture asteroids from the Near-Earth object (NEO) population and pull them into orbit, making them mini-moons,” study authors Carlos de la Fuente Marcos and Raúl de la Fuente Marcos said.
After leaving Earth’s orbit, the 2024 PT5 will remain near our planet for few months. Then, it will leave Earth’s neighborhood until it returns again to our planet’s orbit in about 30 years.
Temporary Mini-moons
The mini-moon events happen in two forms, explained de la Fuente Marcos. The first are long episodes during which the asteroid completes one or two orbits around Earth, which can last for one or more years. They are called a long-capture mini-moon.
Meanwhile, the second form is the short episodes, in which the asteroid does not complete one full orbit around Earth. They last for days, weeks, or even few months. They are called temporarily captured flybys.
De la Fuente Marcos said that short mini-moon events can happen many times per decade. Meanwhile, long mini-moon events are rare.
Past Occurrences
Earth has captured temporarily mini-moons several times before, according to CNN. An asteroid called 2020 CD3 was spotted orbiting Earth in February 2020 and departed a few months later. The 2020 CD3 is a long-capture mini-moon, while the 2024 PT5 is a short-capture one.
Another asteroid, known as 2022 NX1, became a mini-moon in 1981 and 2022. It will return again to Earth’s orbit in 2051. Also, an asteroid called 2006 RH120 orbited Earth for one year, starting in July 2006.
Moreover, the 2024 PT5 will return to our planet’s orbit in 2055. The study expected it will become Earth’s mini-moon for a few days in November 2055. Then, it will orbit the planet again for a few weeks in early 2084.
Possible Impact
The study lead author, Carlos de la Fuente Marcos, said that the mini-moon phenomenon will not have any observable effects on Earth.
Although the asteroid’s diameter is estimated at 11 meters, it will be too small and dim to observe with naked eye, binoculars, or even amateur telescopes. However, the 2024 PT5 will be within the range of typical telescopes used by professional astronomers, de la Fuente Marcos noted.
