Moons orbit planets, but could a moon have its own moon? Surprisingly, yes—at least for a while. Astronomers call these “submoons” or “moonmoons,” and while none have been confirmed in our solar system yet, simulations suggest they should exist. The best candidates are large moons like Titan or Ganymede, which have enough gravity to hold onto tiny orbiting objects. The problem? Tidal forces from the planet usually rip them away. But for a brief period, a moon could have a moon of its own—just don’t expect it to last forever.
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