NASA Confirms Earth Has a New Quasi-Moon, Orbiting for Decades
WASHINGTON – Astronomers have confirmed Earth has a new, temporary companion: a quasi-moon designated 2025 PN7, expected to remain in this orbital dance with our planet for the next 50 years. The finding, detailed in Research Notes of the AAS, offers a unique opportunity to study small body dynamics and test technologies for future space missions.
Unlike a true moon, 2025 PN7 doesn’t orbit Earth directly. It orbits the Sun, but remains in a complex gravitational relationship with our planet, effectively circling Earth as it travels around the Sun. This “quasi-moon” status means it shares Earth’s orbit, completing a yearly cycle alongside us.
This isn’t the first time Earth has hosted such a companion. Earlier research on the longer-lived quasi-moon Kamoʻoalewa revealed lunar-like silicates in its surface composition, suggesting some of these objects may originate as fragments ejected from our Moon long ago.
The predictable path of 2025 PN7 makes it an ideal test subject for refining space mission technologies. Engineers can utilize its stable orbit to practice delicate maneuvers, improve navigation software, and study dust behavior in weak gravity – all crucial steps before venturing deeper into the solar system. Scientists can also leverage these companions to better understand resonant orbits and how factors like solar radiation and planetary tides influence the movement of small asteroids over time.
Despite sharing Earth’s orbital path, 2025 PN7 won’t impact our planet or be visible to the naked eye. It remains distant and faint, posing no threat and not affecting tides or nighttime illumination. Quasi-moons are also distinct from temporary captures, which involve a brief, true orbit lasting only weeks or months before the object drifts away.
The confirmation of 2025 PN7 adds another data point to understanding how small bodies behave in complex gravitational environments, ultimately improving risk assessments for meteoroid streams and clarifying material movement within the inner solar system.
