New 'Quasi-Moon' Discovered in Earth Orbit May Have Been Hiding There for Decades

A dim asteroid, newly discovered as 2025 PN7, could have been tagging along after Earth in orbit for decades, scientists say. If validated, the object would become one of a handful of known “quasi-moons”—bodies that seem to circle Earth but actually orbit the sun while travelling with our planet for a time. At 62 feet wide, 2025 PN7 is smaller than the Chelyabinsk meteor and remains faintly visible – for now — only through telescopes with difficult observation windows. The find underscores the challenge of tracking dim, Earth-adjacent objects.

Astronomers Confirm Faint Asteroid 2025 PN7 as Earth's Smallest and Least Stable Quasi-Moon

According to the Research Notes of the American Astronomical Society (via Phys.org), the asteroid's presence was first documented in late July by the Pan-STARRS1 telescope in Hawaii. The quasi-moon designation was initially suggested by amateur astronomer Adrien Coffinet, who noted that orbital calculations indicated the object has been nearby for about 70 years and could remain in a quasi-satellite state for the next six decades.

2025 PN 7, the faintest and shortest-duration quasi-moon that has ever been observed, is dim just because it appears so only at times when it isn't really feeling well.

Quasi-moons are illuminating with respect to trajectories of bodies in orbital frames; there were 7 found and about as many not yet discovered. Additional objects could be found in the future, especially as attempts like those of the Vera C. Rubin Observatory take place.

The determination that there are real companions in our Earth's local environment is also not consistent with current expectations, which suggests that additional similar paired objects will be found in future large-area sky surveys.