Planets flying in darkness without a star can have moons of their own. The James Webb Telescope stared at the cold ball WISE 0855 for 11 hours — will a shadow flicker? Quiet so far, but proven: if moons are there, we’ll soon catch them.
🎯 WISE 0855 is one of the coldest objects known beyond the Solar System: its temperature is just a few dozen degrees above freezing. If intelligent life were there, it would see a sky without any sun, perpetually shrouded in water-ice fogs.
🎬 Rogue planets with moons are almost a ready-made illustration for Isaac Asimov’s story “The Wanderer”: the characters live on a moon of an orphan planet, warmed only by internal heat.