Long-hidden ‘Moon’ Following Earth for Decades Discovered Recently

The cosmic dance of our moon now features a new partner: a recently discovered quasi-moon, which is trailing Earth in its orbit but is set to depart in a few decades.

On August 29, 2025, the Pan-STARRS astronomical observatory in Hawaii unveiled its findings of the quasi-moon, designated as 2025 PN7. This intriguing celestial body has been quietly journeying alongside our planet for about 60 years, though its faint visibility has made it a challenge for astronomers to detect.

Understanding Quasi-Moons: A Unique Cosmic Phenomenon

A quasi-moon, by definition, is an asteroid that orbits the sun in the vicinity of a planet, acting in some respects like a moon. Despite this resemblance, it maintains its own orbit and will eventually break away from its temporary companionship with Earth.

A graph of 2025 PN7's orbit compared to earth. — IN

2025 PN7, measuring a modest 19 meters (62 feet) in diameter, is expected to remain in close proximity to Earth until 2083, marking a temporary yet fascinating chapter in our planet’s cosmic journey.

A Brief History of Earth’s Quasi-Moons

This newly identified quasi-moon is not the first to accompany our planet. Astronomers have cataloged a total of seven such asteroids, one of which is believed to be a remnant of our original moon, expelled by a violent collision with another celestial body.

Historically, near-Earth objects (NEOs) like 2025 PN7 have sparked considerable interest and, at times, anxiety about extraterrestrial life. The discovery of 1991 VG in the early 1990s was particularly sensational, leading to speculations that it might be a potential alien probe due to its orbit near Earth.

An artist's rendering of an asteroid, courtesy of NASA. — Unsplash.com: NASA Hubble Space Telescope

As intriguing as such theories are, they have mostly been set aside in favor of more scientifically grounded explorations. Presently, the celestial object 3I/ATLAS has caught the attention of scientists as the third known entity to enter our solar system from another star, igniting interest in the possibilities of extraterrestrial technology due to its striking luminosity and rotational characteristics.

Indeed, the continued exploration of quasi-moons like 2025 PN7 enriches our understanding of the solar system and highlights the dynamic interactions between celestial bodies.

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