Astronomers Report Potential First Moon Beyond the Solar System
Astronomers have reported evidence of what may be the first moon detected beyond the Solar System. The unusual object is at least as massive as Jupiter and orbits a brown dwarf, which itself circles a star.
This arrangement does not fit neatly into traditional definitions of planets and moons. If confirmed, the discovery would raise questions about how such a system formed and how astronomers should classify objects with this structure.