What counts as a moon? Huge ‘exosatellite’ sparks debate

TL;DR - A distant Jupiter-mass object is prompting debate over what qualifies as a moon. The discovery could help advance methods for detecting moons beyond the Solar System.

• The object is described as an unusually massive potential “exosatellite.”
• Its classification challenges conventional boundaries between moons and other planetary bodies.
• The item also notes the discovery of a rare transmissible cancer in catfish.
• The provided content does not include observational methods or detailed results.