For the next few months, Earth will have a new moon — a mini one at least.
What is a mini-moon?
When Earth captures a nearby asteroid and pulls it into its orbit, that asteroid is sometimes known as a “mini-moon.”
In a recent report published by the American Astronomical Society, researchers calculated that an asteroid spotted by the NASA-funded Asteroid Terrestrial-impact Last Alert System on Aug. 7 will be pulled into Earth’s orbit, circling the Earth like a moon from Sept. 29 to Nov. 25.
At that point, the asteroid, called 2024 PT5, will “return to a sun-centered orbit, remaining part of the Arjuna asteroid belt,” per LiveScience.
Some scientists say that the 2024 PT5 isn’t technically a mini-moon since it won’t perform a full orbit of the Earth. Instead, it will perform a horseshoe-shaped orbit.
“It certainly won’t complete one full revolution in the Earth-moon system this fall, so I’m not sure I would classify it as a ‘mini-moon’” Lance Benner, principal investigator of the asteroid radar research program at the Jet Propulsion Laboratory, told The New York Times.
Sone scientists, however, suggest 2024 PT5 is more moon-like than previously thought.
The asteroid’s orbit suggests that it is “possibly a piece of ejecta from an impact on the moon,” Paul Chodas, director of the Center for Near Earth Object Studies at NASA’s Jet Propulsion Laboratory, said, per the Times, possibly making the mini-moon a piece of the actual moon.
How to see a mini-moon
Unlike the recent combined supermoon and partial lunar eclipse, you probably won’t be able to see this celestial event from Earth.
The leader author of the study, Carlos de la Fuente Marcos, told Space.com the mini-moon is “too small and dim for typical amateur telescopes and binoculars.”
“However, the object is well within the brightness range of typical telescopes used by professional astronomers,” Marcos said. “A telescope with a diameter of at least 30 inches plus a CCD or CMOS detector are needed to observe this object, a 30 inches telescope and a human eye behind it will not be enough.”