Consider the following; We have Earth with two moons in orbit (discounting the existence of our own moon for the sake of this hypothetical scenario). One moon is the size and mass of Pluto, orbiting around 70,000km from Earth. The other is the size and mass of Pluto's moon, Charon, orbiting around 7,000km from Pluto. For the sake of the scenario, seen as they're exactly the same as Pluto and Charon, I'll just refer to them as such. "Pluto" is tidally locked with Earth, orbiting the same as our moon - around once every 29/30 days. "Charon" is tidally locked with "Pluto", orbiting it every 7 days. From Earth, what would this look like? How would the two moons appear from Earth's surface in terms of their phases and position? Pluto's would remain the same as our moon does anyway (right?), but how would Charon look? Would their orbits be stable in relation to each other and to Earth? How would this affect tides on Earth, with two moons in orbit? Would it affect axial tilt (and thus, seasons) of Earth in any way given the mass and distance of the objects? Would this even be possible, to have a moon tidally locked to another body, which is tidally locked to a large planet?