Moon Could Still Have Molten Interior

Astronomers have calculated that the Moon, pulled by the gravity of the Earth and the Sun, may bulge as much as 10 centimetres over the course of its 27 day journey around our planet. The bulging could be caused by a molten slush surrounding the Moon's core. The measurements were gathered by firing a laser pulse from the Earth to the Moon, and it measures the round-trip distance to an accuracy of 2 centimetres.