Overview
- Astronomers have verified that asteroid 2025 PN7 is a co-orbital "quasi-satellite" of Earth expected to persist in this configuration until about 2083.
- Estimated at 18–36 meters across, 2025 PN7 was discovered by the University of Hawaiʻi’s Pan-STARRS1 survey and ranges roughly 4–17 million kilometers from Earth.
- Quasi-satellites orbit the Sun on Earth-like paths, creating the appearance of a companion despite not being gravitationally bound as a true second moon.
- Separately, interstellar comet 3I/ATLAS—first reported by the ATLAS survey on July 1—will reach perihelion around October 30 on a hyperbolic trajectory and remain no closer than about 240 million kilometers from Earth.
- NASA- and MPC-coordinated teams note astrometric challenges in measuring 3I/ATLAS and have planned training and workshops to refine techniques as global follow-up observations continue.