For decades, Earth’s skies have hidden a quiet traveler a tiny companion following our planet’s journey around the Sun. Astronomers have now confirmed that a small asteroid, known as 2025 PN7, has been moving in sync with Earth for nearly 60 years, making it one of our planet’s so-called quasi-moons.
This surprising discovery adds another chapter to the story of Earth’s cosmic neighborhood and offers scientists a unique opportunity to study objects that share our orbit.
What is a Quasi-Moon?
Unlike our Moon, which is bound to Earth by gravity and completes an orbit around us every 27 days, a quasi-moon does not truly orbit Earth. Instead, it circles the Sun on a path so closely matched with Earth’s orbit that, from our perspective, it seems to tag along with us.
Astronomers sometimes call these objects quasi-satellites. They are not permanent companions but can remain in this orbital dance with Earth for decades or even centuries before drifting away.
Meet 2025 PN7
The newly identified quasi-moon, 2025 PN7, is a small asteroid about 19 meters (62 feet) wide. That makes it tiny compared to the Moon, but still large enough to be of interest to planetary scientists.
Observations and orbital modeling suggest that this asteroid has been in a quasi-satellite relationship with Earth for the past six decades. Even more fascinating, calculations show that it will likely continue traveling alongside us for another 60 years before eventually breaking free from this cosmic companionship.
How Did Astronomers Find It?
2025 PN7 was first detected in August 2025, when sky surveys picked up its faint light. At first, it looked like just another near-Earth asteroid. But when researchers studied its orbit, they noticed something unusual the asteroid’s path was almost perfectly synchronized with Earth’s orbit around the Sun.
By running computer simulations that project the asteroid’s motion backward in time, astronomers discovered that it has likely been shadowing Earth since the early 1960s.
Although we only spotted it recently, 2025 PN7 has been quietly following us for most of modern history.
Why This Discovery Matters
Quasi-moons like 2025 PN7 are more than just curiosities. They provide scientists with valuable opportunities to learn about the dynamics of near-Earth objects and how small asteroids interact with planetary orbits.
Because they stay relatively close to Earth for long periods, these objects could also become future targets for space missions. Visiting a quasi-moon would require less energy than traveling to the main asteroid belt, making them appealing for exploration and study.
Moreover, understanding these companions helps researchers keep track of objects that could one day pose a risk if their orbits shift. Fortunately, 2025 PN7 poses no threat to Earth.
A Cosmic Reminder
Earth’s skies are far from empty. Along with the Moon, thousands of asteroids, comets, and other bodies share our solar journey in ways both predictable and surprising. The discovery of 2025 PN7 shows that even after centuries of sky-watching, our planet can still reveal new neighbors hiding in plain sight.
While our Moon will always remain Earth’s only true natural satellite, quasi-moons like 2025 PN7 remind us that the cosmos is filled with companions whose paths briefly intertwine with ours. For now, this small asteroid will continue to drift alongside us a silent traveler keeping Earth company until its orbit finally carries it away.