An international team of astronomers has found evidence of a moon-like companion orbiting the brown dwarf CD-35 2722 B, 73 light-years from Earth. If confirmed, it would be the first detected exomoon-like object beyond the solar system and could help address the longstanding lack of definitive evidence for moons in other planetary systems.

The suspected “exosatellite” has a mass of at least 0.9 Jupiter masses and appears to orbit every 170 days, making it far larger relative to its host than any familiar moon in the solar system. Researchers used 23 nights of observations between October 2023 and February 2026 with the Very Large Telescope, detecting the brown dwarf’s gravitational wobble; they also ruled out several alternative explanations and found the orbit should be physically stable.