New ‘Mini-Moon’ Found: Asteroid 2025 PN7 to Orbit Near Earth for 60 More Years
Astronomers confirm Earth’s new space companion will tag along until 2083.
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| Though just around 100 feet wide, asteroid 2025 PN7 has been silently shadowing Earth’s orbit for decades. |
Earth Has a New Celestial Companion — But It Won’t Stay Forever
Astronomers have recently spotted a small asteroid, quietly trailing Earth as it orbits the Sun. Acting like a temporary second moon, this newfound space rock is a rare type of cosmic companion — and it’s expected to stick around for a few decades before drifting away.
Named 2025 PN7, the object was first detected on August 2, 2025, by the Pan-STARRS telescope in Hawaii.
Although newly discovered, archived observations reveal that this asteroid has actually been sharing Earth's orbit for around 60 years. According to EarthSky, it’s expected to remain in this unusual co-orbital dance for another six decades before eventually drifting away.
It’s Not a True Moon — But It Sure Acts Like One
While 2025 PN7 might seem like a second moon, it doesn’t technically qualify. Instead, astronomers classify it as a quasi-moon — a rare type of asteroid that doesn’t orbit Earth directly but follows a similar path around the Sun. Because it moves in near-perfect sync with Earth, it gives the illusion of looping around our planet, even though it remains gravitationally bound to the Sun.
According to EarthSky, this synchronized motion occurs because the asteroid shares Earth's orbital path, staying close in a delicate gravitational dance that keeps it nearby without being pulled into full orbit.
A Rare Member of the Arjuna Asteroid Class
2025 PN7 belongs to an exceptionally uncommon group of asteroids known as the Arjuna class — space rocks with Earth-like orbits that circle the Sun at nearly the same distance as our planet. Their orbits are incredibly stable, with very low tilt and minimal eccentricity.
Some scientists even refer to them as a kind of "secondary asteroid belt," since they stay closer to Earth than any other known asteroid population. This classification comes from research by Carlos and Raúl de la Fuente Marcos, published in Research Notes of the American Astronomical Society on September 2, 2025.
Small, Dim, and Hard to Spot
Despite its interesting orbit, 2025 PN7 is quite small — measuring just 50 to 100 feet wide, or roughly the size of a semi-truck or small house. It’s also extremely dim, which explains why it went unnoticed for decades despite lingering near Earth for so long.
An Orbit That’s Always Changing
What makes 2025 PN7 even more fascinating is the way its orbit evolves. At times, it follows a horseshoe-shaped path relative to Earth — a pattern where it appears to drift ahead of or behind our planet without making a full loop. At other times, it behaves more like a quasi-satellite, performing wide, looping orbits around Earth’s path.
These orbital patterns are not permanent. Astronomers expect 2025 PN7 to shift back into a horseshoe orbit in the future as gravitational forces gradually alter its trajectory.
Locked in Sync, But Not in Orbit
According to the study, asteroid 2025 PN7 is currently in a 1:1 orbital resonance with Earth — meaning it completes one full orbit around the Sun in the same time we do: about one year. This synchronized motion allows it to remain near Earth over long periods, though it’s never gravitationally bound to our planet like the Moon. It’s a neighbor, not a satellite.
A Rare Addition to Earth’s Quasi-Moon Club
2025 PN7 joins a small, exclusive group of known quasi-moons — including Kamo'oalewa, Cardea, and 2023 FW13 — that have temporarily shared Earth's solar orbit. Each of these objects has its own unique trajectory and time frame of companionship with Earth.
The study notes that PN7’s current quasi-satellite phase is expected to last around 128 years — shorter than some other quasi-moons, but still a significant stretch in cosmic terms.
A Slow-Motion Dance With Earth
Unlike the typical asteroid that speeds past our planet and continues on its way, 2025 PN7 is caught in a long, graceful loop near Earth, lingering just close enough to be considered a long-term guest.
Though it won’t remain in this configuration forever, scientists say its presence provides a rare opportunity to study how small asteroids can temporarily synchronize with Earth’s orbit — offering insights into orbital dynamics, asteroid behavior, and potential future mission targets.
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