Astronomers Identify New Quasi-Moon Near Earth: 2025 PN7

Astronomers have discovered a new quasi-moon, designated 2025 PN7, which has been orbiting near Earth for approximately 60 years. This small celestial body, measuring about 62 feet (19 meters) in diameter, is classified as a near-Earth asteroid and follows a solar orbit that keeps it in close proximity to Earth rather than directly orbiting the planet. First identified by the Pan-STARRS Observatory in Hawaii on August 29, 2025, its presence in the cosmic neighborhood can be traced back to at least 2014 through archival observations.

Understanding Quasi-Moons

Unlike traditional moons, which orbit planets directly, a quasi-moon maintains a solar orbit that closely aligns with a planet’s path. In the case of 2025 PN7, its orbit around the Sun allows it to remain near Earth for decades, creating the appearance of a celestial companion. These quasi-moons are influenced by both the gravity of the planet and the Sun, establishing a temporary yet stable orbital relationship.

Lead author Carlos de la Fuente Marcos from the Complutense University of Madrid highlighted the significance of this discovery, explaining that the faintness of 2025 PN7 accounts for its prolonged period of undetection. The asteroid was first brought to the attention of the astronomical community by French journalist Adrien Coffinet via the Minor Planet Mailing List, underscoring its unique orbital dynamics.

Characteristics of 2025 PN7

At just 62 feet wide, 2025 PN7 is notably smaller and less stable compared to other known quasi-moons. Its orbit around the Sun mirrors Earth’s, completing a solar circuit in roughly one year. Scientists estimate that it will continue in its quasi-orbit for another 60 years before gravitational forces alter its trajectory. Unlike more stable quasi-moons like Kamo’oalewa, 2025 PN7’s shorter lifespan presents a unique opportunity for detailed study.

The discovery of 2025 PN7 adds to the limited catalog of known quasi-moons, providing astronomers with critical data about near-Earth objects, their orbital behavior, and potential implications for planetary defense strategies. Observations of such bodies can also inform future exploratory missions aimed at understanding the dynamics of small celestial companions.

Despite its current faintness, astronomers intend to monitor 2025 PN7’s orbit and behavior closely. This discovery raises the potential for identifying more quasi-moons in the future. Researchers are optimistic that subsequent observations will uncover additional characteristics, including composition, spin, and possible origins.

By tracking these small celestial bodies, scientists aim to enhance our understanding of Earth’s immediate cosmic environment and the interactions of near-Earth asteroids with our planet. The ongoing study of 2025 PN7 and its ilk will likely yield insights into how these temporary satellites can maintain proximity to Earth without becoming traditional moons.