Photo: freepik
NASA has confirmed the discovery of a new quasi-satellite of Earth — asteroid 2025 PN7, which orbits the Sun along almost the same path as our planet. According to scientists, the object has been accompanying Earth for about 60 years and will remain nearby until at least 2083, reports BGR.
The finding, published in the Research Notes of the American Astronomical Society, describes 2025 PN7 as a rare member of a class of celestial bodies known as quasi-moons. These objects don’t orbit Earth directly but share a similar orbit around the Sun, creating the illusion of a second Moon.
The asteroid was discovered on August 2, 2025, using the Pan-STARRS 1 telescope located on the Haleakalā volcano in Hawaii. Its diameter is estimated at 18–36 meters — roughly the size of a small house. The distance between PN7 and Earth varies from 4 to 17 million kilometers.
Researchers emphasize that PN7 poses no danger to our planet. Its orbit is stable, and the probability of collision with Earth is virtually zero.
“While the idea of a ‘second Moon’ sounds sensational, PN7 is simply a regular asteroid moving in orbital resonance with Earth,” the study explains.
Based on orbital calculations, 2025 PN7 belongs to the Arjuna-type group of asteroids — bodies whose orbits closely match Earth’s (0.985–1.013 astronomical units). These have nearly circular orbits and minimal inclination relative to the Earth’s orbital plane.
The Arjuna system already includes several similar objects such as Cardea, Kamoʻoalewa, 277810, 2013 LX28, 2014 OL339, and 2023 FW13 — all moving in a 1:1 mean-motion resonance with Earth, meaning they circle the Sun at the same rate but without being gravitationally bound to our planet.
PN7 is expected to remain a quasi-satellite only temporarily — until around 2083, when gravitational influences from the Sun and other planets will push it onto a new trajectory.
Astronomers note that discovering and tracking such objects is crucial for understanding the dynamics of the Solar System. Quasi-moons like PN7 can help scientists study the evolution of near-Earth asteroids and identify potential resources for future space missions.
According to NASA’s Jet Propulsion Laboratory (JPL), PN7’s movement and that of other quasi-satellites are monitored continuously through automated observation systems and specialized astronomical algorithms using the Astroquery platform and JPL’s Small-Body Database.
