University of Hawaii astronomers discovered asteroid 2025 PN7 in August 2025. About 118 feet (36 m) across, it is a quasi-satellite — orbiting the Sun while temporarily sharing Earth’s orbital neighborhood. Likely in this configuration for ~60 years, it should drift away around 2083. At roughly 10^15 times less massive than the Moon, it poses no threat but is useful for improving orbital models and detection methods.
Not a Second Moon: Quasi‑Satellite 2025 PN7 Will Hover Near Earth Until About 2083
University of Hawaii astronomers discovered asteroid 2025 PN7 in August 2025. About 118 feet (36 m) across, it is a quasi-satellite — orbiting the Sun while temporarily sharing Earth’s orbital neighborhood. Likely in this configuration for ~60 years, it should drift away around 2083. At roughly 10^15 times less massive than the Moon, it poses no threat but is useful for improving orbital models and detection methods.
22:45, 03.11.2025Science
Summary: Astronomers have identified a small asteroid, 2025 PN7, that has been following a Sun-centered path close to Earth's orbit for decades. Discovered in August 2025 by researchers at the University of Hawaii, this object is a temporary quasi-satellite — not a true moon — and is expected to remain near Earth until roughly 2083.
Discovery and basic facts
The asteroid 2025 PN7 was discovered in August 2025 by a team at the University of Hawaii. Current estimates put its diameter at about 118 feet (roughly 36 meters), minuscule compared with the Moon (which has a radius of about 1,080 miles or ~1,740 km).
What is a quasi‑satellite?
A quasi-satellite is an object that primarily orbits the Sun but follows a path very similar to Earth's, so it appears to orbit our planet for an extended period. Unlike the Moon — a bound natural satellite held in a stable orbit by Earth's gravity — a quasi-satellite is only temporarily co-moving with Earth and will eventually drift away as orbital dynamics change.
How long will 2025 PN7 stay near Earth?
Analyses indicate that 2025 PN7 has likely been in this quasi-orbital configuration for about 60 years and is expected to remain a temporary companion until around 2083. After that time, gravitational interactions with Earth, the Sun and other bodies will alter its trajectory and carry it away from our neighborhood.
“In the long term, the orbits will drift, and the quasi-moons will move away,”
Is there any danger?
No. 2025 PN7 is far too small to affect Earth’s tides, climate, or daily life. Researchers estimate it is roughly a quadrillion (10^15) times less massive than the Moon, so its gravitational influence on Earth is negligible. It poses no known threat to our planet.
Why this matters
Although harmless, transient objects like 2025 PN7 are scientifically valuable. They help astronomers refine orbital models, test detection methods for small near-Earth objects, and improve strategies for planetary defense. 2025 PN7 is one of seven known quasi-moons associated with Earth, and more may exist undetected because small objects are easy to miss in the vastness of space.
Bottom line: 2025 PN7 is a temporary, small quasi-satellite that will remain in Earth’s vicinity for decades but is not a second moon. Studying it helps improve our understanding of near-Earth space and enhances asteroid detection capabilities.