A newly identified “quasi-moon” is being described as a second moon in Earth’s orbit, and it could stay there for decades.
NASA confirmed this week that a space rock, 2025 PN7, discovered by the University of Hawaii, is officially a “quasi-moon” — a rare type of celestial companion that travels almost exactly in sync with Earth. While it’s not a true moon, it keeps pace with our planet, looping around the Sun in a path so similar that it appears to shadow Earth.
According to UnionRayo.com, the University of Hawaii team discovered the object using the Pan-STARRS observatory. on the Haleakala volcano. Observations of 2025 PN7 were captured on Aug. 29, and archival data revealed that it has been following an Earth-like orbit for decades.
Scientists estimate the object is about 18 to 36 meters wide, roughly the height of a small building. According to EarthSky.com, quasi-moon 2025 PN7 is exceedingly dim, which has helped it escape detection until now. It’s about magnitude 26. That puts it far out of range of amateur telescopes.
At its closest, it comes within 4 million kilometers, roughly ten times farther than the Moon. At its farthest, it can drift out to 17 million kilometers. NASA says there is no known impact risk, but the find gives scientists a rare chance to study a small near-Earth object up close.
Models suggest it has been in our neighborhood for decades and could stick around until about 2083. 2025 PN7 joins a small group of known quasi-satellites of Earth, including 164207 Cardea, 469219 Kamo‘oalewa, (277810) 2006 FV35, 2013 LX28, 2014 OL339, and 2023 FW13. CNN notes that Kamo‘oalewa, which is also thought to be an ancient lunar fragment. Kamo‘oalewa is one of the destinations of China’s Tianwen-2 mission launched in May, which aims to collect and return samples from the space rock in 2027.
