Astronomers have announced the discovery of a new “quasi-moon” that travels alongside Earth. This celestial body, designated as asteroid 2025 PN7, has been observed on a synchronized path with our planet as both orbit the Sun. Initially detected in August 2025 by the Pan-STARRS observatory in Hawaii, this small asteroid measures approximately 20 meters in width and is believed to have been accompanying Earth for around 60 years.
A quasi-moon, often referred to as a quasi-satellite, differs from a traditional moon. Unlike the Moon, which is gravitationally tethered to Earth and directly orbits it, a quasi-moon orbits the Sun in a manner similar to Earth. The trajectory of 2025 PN7 keeps it close to our planet for significant durations, creating the visual effect that it is orbiting Earth.
From our perspective, 2025 PN7 appears to trace a figure-eight or horseshoe pattern around Earth, a phenomenon resulting from the gravitational influences of both Earth and the Sun. This new quasi-moon has an orbital period that closely matches that of Earth, taking about a year to complete its journey around the Sun. At times, it may drift ahead of Earth, while at other moments, it falls behind, maintaining a delicate gravitational equilibrium.
In contrast to mini-moons, which may temporarily orbit Earth for a limited time before departing into space, quasi-moons like 2025 PN7 can remain in this gravitational relationship for centuries. Previous studies have identified other transient companions such as Kamo”oalewa (2016 HO3) and 2023 FW13, but 2025 PN7 is notable for its stability and longevity.
Astronomers have reassured the public that this new quasi-moon poses no danger to Earth, maintaining a distance of millions of kilometers from our atmosphere and the orbit of the Moon. Researching quasi-moons like 2025 PN7 provides valuable insights into orbital resonance, the intricate gravitational dynamics that allow these asteroids to remain in sync with our planet. Additionally, their proximity positions them as potential targets for future space exploration missions, as they may offer clues about the early history of our Solar System.
While Earth”s true Moon stands as the planet”s sole natural satellite, the discovery of 2025 PN7 serves as a reminder of the dynamic nature of the space surrounding our planet, where other cosmic travelers occasionally align with Earth”s journey through the cosmos.
