The volcanoes that litter the Moon's "other side" not visible from Earth are of the rare silicate types, not the basaltic volcanoes seen on the visible side of the moon.
According to researchers, the new findings reveal that the Moon is home to more complex geological activity than initially thought. A team led by Bradley L. Jolliff, a planetary scientist at Washington University in St. Louis, has reported the latest findings in the journal Nature Geoscience.
According to Jolliff, the primary author of the report, most of the volcanic activity on the moon has been found to be basaltic in nature. He told space.com that the new findings show the complexities of the Moon's geological activities. "Finding other volcanic types is interesting as it shows the geologic complexity and range of processes that operate on the moon, and how the moon's volcanism changed with time."
According to researchers, the region where rare volcanic activity has been found is thought to have a concentration of radioactive element thorium.
"We've known for awhile that the Compton-Belkovich had an unusually high thorium content. ... Now we can positively say that thorium is related to these silicic volcano materials," said study co-author Timothy Glotch of Stony Brook University, according to space.com.
The Far Side
The "far side" of the Moon is that part of the Moon which is not visible from Earth, or what is called the lunar hemisphere permanently unseen from Earth. This happens because the Moon's rotation is affected by tidal forces between Earth and the Moon.
In 1998, NASA's Lunar Prospector probe had taken photographs of the far side. These images revealed a region between two ancient impact craters, known as the Compton-Belkovich region, that bore signs of massive volcanic activity.
The latest images obtained by NASA have gone to prove that volcanoes of a rare type had been active on the far side, which resulted in dome-like formations above the surface. According to Joliff, the lava could have risen from the innards of the Moon and pooled beneath the surface, causing dome-like bumps to emerge.
[MUST READ] Volcanoes Found on Far Side of Moon