2025 PN7
A small Arjuna asteroid and Earth's most recently discovered quasi-satellite.
2025 PN7 is a small asteroid that orbits near Earth and is the latest known quasi-satellite of our planet. It was first spotted on 2 August 2025 using the Pan-STARRS 1 telescope at Hawaii’s Haleakalā Observatory. The asteroid belongs to the Arjuna group, a class of near-Earth objects whose orbits closely resemble Earth’s own path around the Sun.
Discovered by Pan-STARRS 1, the object initially carried the internal designation P12dHmP. The Minor Planet Center (MPC) formally announced its discovery in a Minor Planet Electronic Circular on 29 August, at which point it received the provisional designation 2025 PN7.
In terms of orbit, 2025 PN7 is classified as an Apollo asteroid. It has a semi-major axis of 1.003 AU, an orbital eccentricity of 0.108, and an inclination of roughly 2°, placing it among the low-eccentricity, low-inclination Arjuna asteroids. Unlike the Moon, it is not gravitationally bound to Earth. Instead, it maintains a 1:1 mean-motion resonance with our planet, making it a quasi-satellite—from Earth’s perspective, it appears to linger nearby.
2025 PN7 joins a small list of known Earth quasi-satellites, which includes 164207 Cardea, 469219 Kamoʻoalewa, (277810) 2006 FV35, 2013 LX28, 2014 OL339, and 2023 FW13. These objects are temporarily co-orbital with Earth but are not true moons. Some Arjuna asteroids with particularly Earth-like orbits can occasionally become temporary mini-moons, gravitationally captured for months to years.
At its closest approach, 2025 PN7 comes within about 299,000 km of Earth; at its farthest, it can be tens of millions of kilometers away. Over time, gravitational perturbations may cause it to shift between a quasi-satellite and a horseshoe orbit.
- Discovery date
- 2 August 2025
- Discovery site
- Haleakalā Observatory, Hawaii, United States
- Discovery telescope
- Pan-STARRS 1
- Formal announcement date
- 29 August 2025
- Provisional designation
- 2025 PN7
- Semi-major axis
- 1.003 AU
- Orbital eccentricity
- 0.108
- Orbital inclination
- approximately 2°
- Closest approach distance
- approximately 299,000 km
Lore & Background
2025 PN7 was discovered on 2 August 2025 by the Pan-STARRS 1 telescope at Haleakalā Observatory in Hawaii. The asteroid was formally announced by the Minor Planet Center (MPC) in a Minor Planet Electronic Circular on 29 August. Upon discovery, it was first given the temporary internal designation P12dHmP, then assigned the provisional designation 2025 PN7.
2025 PN7 is an Apollo asteroid with a semi-major axis of 1.003 AU, an orbital eccentricity of 0.108, and an orbital inclination of approximately 2°, placing it in the low-eccentricity, low-inclination Arjuna class. Unlike Earth's natural satellite, the Moon, 2025 PN7 is not gravitationally bound to Earth. It maintains a 1:1 mean-motion resonance with Earth, making it a quasi-satellite. From Earth's perspective, the asteroid appears to hover nearby.
2025 PN7 joins a small group of known quasi-satellites of Earth, including 164207 Cardea, 469219 Kamoʻoalewa, (277810) 2006 FV35, 2013 LX28, 2014 OL339, and 2023 FW13. Quasi-satellites like 2025 PN7 are temporarily co-orbital with Earth but are not true moons. Some Arjuna-class asteroids with particularly Earth-like orbits can occasionally become temporary mini-moons, gravitationally captured by Earth for months to years.
Reader's Guide
2025 PN7 is significant as the most recently discovered quasi-satellite of Earth, adding to a small group of known objects that share Earth's orbit in a 1:1 mean-motion resonance. Its discovery by the Pan-STARRS 1 telescope highlights the ongoing survey efforts to detect near-Earth objects. As an Arjuna-class asteroid, it has an orbit very similar to Earth's, with low eccentricity and inclination. During its closest approach, it comes within approximately 299,000 km of Earth, while at its farthest it can be tens of millions of kilometers away. Over time, it may transition between quasi-satellite and horseshoe orbits due to gravitational perturbations. This behavior underscores the dynamic nature of co-orbital objects and their potential to become temporary mini-moons, though 2025 PN7 itself is not gravitationally bound to Earth. Its discovery and classification contribute to the understanding of Earth's co-orbital population and the processes that govern these transient companions.
Did You Know?
- It is a member of the Arjuna asteroid group, which consists of near-Earth objects with orbits very similar to Earth's.
- 2025 PN7 is not gravitationally bound to Earth but maintains a 1:1 mean-motion resonance, making it a quasi-satellite.
Frequently Asked Questions
What is 2025 PN7?
2025 PN7 is a small Arjuna-group asteroid that currently functions as Earth's most recently identified quasi-satellite. It is a near-Earth object whose orbital path closely mirrors our planet's own journey around the Sun.
How and when was 2025 PN7 discovered?
The asteroid was first detected on 2 August 2025 by the Pan-STARRS 1 survey telescope operating out of Haleakalā Observatory in Hawaii. The Minor Planet Center then issued a formal discovery announcement via a Minor Planet Electronic Circular on 29 August 2025.
Why is 2025 PN7 considered important?
It holds the distinction of being the latest known quasi-satellite of Earth, making it a key data point for astronomers studying how small bodies can remain loosely gravitationally associated with our planet over long timescales.
What does 2025 PN7's orbit look like?
With a semi-major axis of roughly 1.003 AU, the asteroid traces an orbit that hovers very close to Earth's own 1 AU path. This is characteristic of the Arjuna group, a class of near-Earth objects whose trajectories closely resemble Earth's.
What was 2025 PN7 called before its official designation?
Before the MPC's formal circular, the object went by the internal survey code P12dHmP. The provisional designation 2025 PN7 was assigned at the time of the 29 August 2025 announcement.
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