I hope we are not talking UNscience fiction here:
"Between 1969 and 1977, seismometers installed on the
Moon by the Apollo missions recorded moonquakes. The
Moon was described as "ringing
like a bell" during some of those quakes, specifically the shallow ones. This phrase was brought to popular attention in March 1970, in an article in Popular Science." Google/Wiki
"The Hollow Moon concept is similar to the better-known
Hollow Earth hypothesis, which was a recurring plot device in pre-spaceflight
science fiction. The first discussion of a hollow Earth was by scientist
Edmond Halley in 1692, while the first publication to mention a hollow Moon was not until
H. G. Wells' 1901 novel
The First Men in the Moon."
Apollo expeditions to the Moon 12.3:
"The best guess was that the Moon was composed of rubble a lot deeper below its surface than anybody had assumed. The internal structure, being fractured instead of a solid mass, could bounce the seismic energy from piece to piece for quite a while."
This effect is also known on Earth:
"Seismic waves from the biggest
earthquakes (over magnitude 8.3) can bounce around inside
the earth for up to a month. This makes
the earth "
ring". However, you need special instruments to hear the
ring because the tone is very low — about 1 cycle per hour." Wiki
Maybe geologists/seismologists have a different perspective on the word ring. Perhaps a synonym for vibrate - even at low frequencies. Sorry if this is bad news for any "hollow Earth" watchers.
Cat