In article <dvabte$8r6$1@xxxxxxxxxxxxxxxxxxx>,
al <almond@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>>The moon, however, is dry, cool and mostly rigid, like a chunk of stone
>>or iron. So moonquakes set it vibrating like a tuning fork. Even if a
>>moonquake isn't intense, "it just keeps going and going," Neal says.
>I thought that the density of the moon was less than the Earth? Like iron?
It's a simile, not meant to be taken literally.
>How can he tell that the moon is dry subsurface?
Because we've got plenty of bits and pieces from the subsurface, excavated
by impacts and mixed in with the rest. And *all* the lunar samples are
dry as a bone -- drier, in fact.
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. | henry@xxxxxxxxxxxxx