2025 PN7
Small near-Earth asteroid
From Wikipedia, the free encyclopedia
2025 PN7 is a small near-Earth asteroid and the most recently discovered quasi-satellite of Earth. First observed on 2 August 2025 by the Pan-STARRS 1 telescope at Haleakalā Observatory in Hawaii, 2025 PN7 is a member of the Arjuna asteroid group—near-Earth objects with orbits very similar to Earth's.
2025 PN7 photographed by the Dark Energy Survey on 17 November 2018 | |
| Discovery[1] | |
|---|---|
| Discovered by | Pan-STARRS 1 |
| Discovery site | Haleakalā Observatory |
| Discovery date | 2 August 2025 |
| Designations | |
| NEO (Apollo[2] · Arjuna[3]) | |
| Orbital characteristics[2] | |
| Epoch 21 November 2025 (JD 2461000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 11.72 yr (4,279 days) |
| Earliest precovery date | 11 December 2013 |
| Aphelion | 1.109 AU |
| Perihelion | 0.893 AU |
| 1.001 AU | |
| Eccentricity | 0.108 |
| 1.002 yr (365.799 d) | |
| 217.230° | |
| 0° 59m 2.925s / day | |
| Inclination | 1.98° |
| 112.25° | |
| 79.888° | |
| Earth MOID | 0.00282 AU (422,000 km) |
| Physical characteristics[3] | |
| ~19 m | |
| 26.36±0.30[2] | |
Discovery
2025 PN7 was discovered on 2 August 2025 by the Pan-STARRS 1 telescope at Haleakalā Observatory in Hawaii, United States.[3] The asteroid was formally announced by the Minor Planet Center (MPC) in a Minor Planet Electronic Circular on 29 August.[4]
Upon discovery, the asteroid was first given the temporary internal designation P12dHmP.[5] Once it was formally announced on 29 August, it was assigned the provisional designation 2025 PN7 by the MPC.[4]
Orbit and classification
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.[3]
Relationship to Earth
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.[6]
During its closest approach, 2025 PN7 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.[3]
See also
- Temporary satellite – objects that become temporarily gravitationally bound to a planet before later escaping
