It might be hollow or it might have a rigid core, because it rings like a bell. Hard to tell. I'm surprised that we have not sent a mission to explore the resonance issue. That could be done by having seismographs on the surface then setting off charges. Unless that would be considered an act of war by the Lunarians.
It might be hollow or it might have a rigid core, because it rings like a bell. Hard to tell. I'm surprised that we have not sent a mission to explore the resonance issue. That could be done by having seismographs on the surface then setting off charges. Unless that would be considered an act of war by the Lunarians.