A gigantic chunk of old granite that was hidden beneath the surface of the Moon has been discovered by scientists, providing evidence of a sort of volcanism that has never before been observed there. This enigmatic, heat-emitting chunk of granite has been found by an orbiting satellite.
According to the Planetary Scientists, the 50-km-diameter granitic system discovered below the far-side feature known as the Compton-Belkovich Volcanic Complex likely formed from the cooling of molten lava that fed a volcano or volcanoes that erupted approximately 3.5 billion years ago.
"We have discovered extra heat coming out of the ground at a location on the Moon believed to be a long dead volcano that last erupted over 3.5 billion years ago. It's around 50km across, and the only solution that we can think of that produces that much heat is a large body of granite, a rock that forms when a magma body-the unerupted lava-below a volcano cools. Granite has high concentrations of radioactive elements like uranium and thorium compared to other rocks in the lunar crust, causing the heating we can sense at the lunar surface," said Lead researcher Dr Matt Siegler (of the Planetary Science Institute, Tucson, Az).
According to the experts, outside of Earth, the Solar System is almost devoid of granites, which are formed when igneous activity results in magma.
Previously, only several grains of granite were detected in the hundreds of kilograms of rocks returned by NASA's Apollo missions, and remote sensing studies since have found only a few small granite or granite-like features on the Moon.
