For centuries, Earth has been known as a planet with a single natural satellite, the Moon. Recent findings from NASA indicate that this perception may be changing. The planet is being accompanied by a group of eight “quasi-moons,” which are small asteroids that follow Earth in its orbit around the Sun and can sometimes appear to be orbiting our planet.
The newest addition to this group is an asteroid named 2025 PN7, which, if confirmed, would bring the total number of these cosmic companions to eight. This asteroid has been identified as part of a hidden collective of celestial bodies that have been orbiting Earth, some of which have gone unnoticed for decades.
According to the Planetary Society, quasi-moons represent a sort of gravitational illusion. These asteroids are primarily in orbit around the Sun, but their synchronized movement with Earth creates the appearance that they are circling our planet from certain perspectives. Astronomer Carlos de la Fuente Marcos from the Complutense University of Madrid described them as “cosmic hitchhikers” that mimic the behavior of a moon while actually orbiting the Sun.
The discovery of 2025 PN7 was documented on September 2, 2025, in a rapid-publication journal known as the Research Notes of the American Astronomical Society (AAS). First detected by the Pan-STARRS1 telescope at Haleakalā Observatory in Hawaii on July 30, this newly discovered asteroid measures approximately 62 feet (19 meters) in width, comparable to the 2013 Chelyabinsk meteor that exploded over Russia. Its brightness magnitude is 26, making it too faint to be seen without advanced telescopic equipment.
French journalist and amateur astronomer Adrien Coffinet was the first to notice the orbital pattern of 2025 PN7, sharing his calculations on the Minor Planet Mailing List on August 30. He noted that this asteroid is likely to act as a quasi-satellite of Earth, expected to trail our planet for the next 60 years and possibly having done so for the past seven decades.
If 2025 PN7 is officially recognized as a quasi-moon, it will join seven others that are already known to co-orbit Earth. Among these is (469219) Kamoʻoalewa, an asteroid approximately 165 feet long that has been following our planet for nearly a century, and 2023 FW13, which scientists believe has been traveling alongside Earth since 100 BCE.
In addition, several other transient companions, sometimes referred to as “minimoons,” drift in and out of Earth”s orbital path, collectively forming what is informally known as “Earth”s Eight-Moon Club.” The identification of 2025 PN7 raises important questions about how we define a moon. Traditionally, a moon is viewed as a natural object that orbits a planet, but quasi-moons challenge this definition by orbiting the Sun while appearing to be gravitationally tethered to Earth.
This complex relationship suggests that our understanding of satellites may need to evolve as detection technologies advance. Currently, both NASA and the International Astronomical Union (IAU) recognize 422 planetary moons across the solar system, in addition to 531 small-body satellites orbiting various asteroids and dwarf planets. As discoveries continue, astronomers estimate that there may be as many as 10,000 natural satellites in our solar system waiting to be found.
“Quasi-moons challenge our assumptions,” de la Fuente Marcos remarked. “They show that Earth”s interactions with its surroundings are far more intricate and captivating than we ever imagined.” These small, enigmatic companions serve as a reminder that the universe is still full of surprises, even in our own cosmic neighborhood.
