Earth Gains a New Companion: The Discovery of Quasi-Moon 2025 PN7

In a remarkable astronomical find, scientists have unveiled the existence of a previously unknown quasi-moon, designated 2025 PN7, which has been silently shadowing Earth’s orbit for decades. This intriguing celestial object was first observed by the Pan-STARRS observatory in Hawaii on August 2, 2025, and its discovery has sparked excitement in the scientific community, leading researchers to delve into archival data that revealed its presence as far back as 2014.

2025 PN7 is part of an elite group of approximately seven quasi-satellites that share Earth’s orbit around the Sun. Unlike Earth’s one natural satellite, the Moon, quasi-moons do not orbit the planet itself; instead, they are influenced by Earth’s gravitational pull as they travel along a similar path around the Sun. This unique relationship allows them to act as temporary companions to our planet, moving in sync without being captured by its gravity.

Measuring around 62 feet (19 meters) in width, 2025 PN7 resides at a distance that varies between 2.8 million miles and 37.2 million miles from Earth. It was located in the constellation Piscis Austrinus, visible from the Southern Hemisphere. The data collected suggests that this space rock has maintained a stable orbit for an impressive 60 years, with projections indicating it will continue on this trajectory for another 60 years before drifting away from our planet’s orbit.

The discovery of 2025 PN7 adds to the growing list of known quasi-moons, which are often confused with mini-moons. Mini-moons are temporarily captured by Earth’s gravity, orbiting for a brief period—ranging from weeks to months—before breaking free. In contrast, quasi-moons like 2025 PN7 are more permanent fixtures in our orbital neighborhood, moving alongside Earth as it travels through space.

One of the most notable quasi-moons known to date is Kamoʻoalewa, formally identified as 2016 HO3. Discovered in 2016, Kamoʻoalewa measures between 131 and 328 feet (40 to 100 meters) across. China’s Tianwen-2 mission, launched in May 2025, aims to rendezvous with Kamoʻoalewa and collect samples, which are expected to return to Earth in 2027. This mission seeks to uncover vital clues about the origins of our solar system.

The discovery of 2025 PN7 not only enhances our understanding of the dynamics of near-Earth objects but also opens up new avenues for research into the complex interactions between celestial bodies. As scientists continue to study this quasi-moon, we are reminded of the vast and mysterious universe that surrounds us, filled with objects that can reveal secrets about our cosmic history. With 2025 PN7 now on our radar, the journey of exploration and discovery continues, shedding light on the wonders of the solar system.