The sky has a discreet visitor who has given much to talk about: the asteroid 2025 PN7, an object that travels almost at the pace of the Earth and that fits into the category of quasi-moon, although it is not a second natural satellite.
His first recent record came from Pan-STARRS 1 (Haleakalā, Hawaii) on August 2, and its nature as a quasi-satellite has been detailed by the Spanish astronomers Carlos and Raúl de la Fuente Marcos in Research Notes of the AAS, reinforcing European interest in this curious companion.
What is 2025 PN7 and how does it move?
It is a small rocky body, about 20 meters in diameter, which is part of the Arjuna group, a group of asteroids whose orbits around the Sun are very similar to Earth's.
Unlike the Moon, 2025 PN7 does not orbit the Earth; it orbits the Sun almost in sync with our planet, which from here creates the impression that it is “accompanying us”. Even at its closest approaches, it remains several times the distance that separates us from the Moon.
Its brightness is extremely faint: it reaches a apparent magnitude close to 26, a record within the reach of very few telescopes, which is why it has gone unnoticed for decades despite being in our solar neighborhood.
Seen from Earth, its movement draws a apparent elliptical loop, the result of the slight difference in speed and position relative to our orbit; it's a geometric effect, not a stable gravitational capture like that of the Moon.
How long will it be around?
Dynamic models indicate that 2025 PN7 has been with us for a long time. around six decades and will continue in this configuration for several more, with the expectation of remaining until approximately 2083 before gradually becoming phased out.
Specialists emphasize that does not represent danger: even at its closest point it remains very far away in practical terms, and any relevant change in its trajectory would be detected well in advance by the surveillance networks.
What the agencies say and who names them
Contrary to some headlines, the NASA has not issued an official statement proclaiming a “second moon.” The authority for designations and classifications in the Solar System rests with the International Astronomical Union (IAU).
Therefore, the correct name for 2025 PN7 is quasi-moon or quasi-satellite: accompanies the Earth on its solar journey, but is not gravitationally bound like our natural satellite.
Interest for Spain and Europe
The participation of the de la Fuente Marcos brothers highlights the importance of research in Spain and the monitoring from European infrastructures dedicated to NEOs, a context in which 2025 PN7 offers valuable data on orbital dynamics.
Beyond the eye-catching headline, this small object opens the door to Study opportunities about how the Earth interacts with rocks near the Sun and about possible observation strategies; its size, however, makes it difficult to see with the naked eye.
Everything points to 2025 PN7 being a fellow passenger, without risk, detected thanks to Pan-STARRS and studied by Spanish researchers; if calculations are correct, it will keep up with us until around 2083 before continuing its solo solar path.
