Asteroid 2025 PN7: Earth’s Newest Quasi-Satellite
Why in the news
The small near-Earth asteroid 2025 PN7 is in the news as Earth’s newest quasi-satellite, the seventh known. It was announced by the Minor Planet Center on 29 August 2025.
Key facts
- Found on 2 August 2025 by Pan-STARRS 1 at Haleakala Observatory, Hawaii.
- It orbits the Sun, not Earth, in 1:1 mean-motion resonance with our planet, so it seems to hover nearby.
- It is not gravitationally bound to Earth, unlike the Moon.
- Size: about 19 metres; orbital period about 365.8 days.
- Reported to remain a quasi-satellite for 128 years.
About quasi-satellites
Six others are known: Kamo’oalewa, Cardea, 2006 FV35, 2013 LX28, 2014 OL339 and 2023 FW13. Studying them helps scientists understand orbital resonance and near-Earth object dynamics, and such objects are seen as possible targets for future missions. The Arjuna class refers to asteroids on Earth-like orbits.
Exam angle
- Quasi-satellite is not a moon: it is not captured by Earth’s gravity.
- Remember the telescope (Pan-STARRS 1) and site (Hawaii).