According to a recent discovery by NASA’s Lunar Reconnaissance Orbiter, scientists now have photos showing silicate volcanoes on the far side of the moon. Silicate volcanoes are a type that do not ooze magma; deeming them “dead” by scientists. Hhe silicate volcanoes on the far side of the moon are estimated to be around 800 years old, extending the volcanic activity of the moon by 200 million years.The moons far side was not visible from the Earth due to tidal forces between it and the moon, until 1959 when the Soviet Union’s Luna 3 Spacecraft took pictures of the region.The nature of the terrain vividly comes to life when orbiter camera images are overlaid on a digital terrain model. At the center of the province is an irregular depression that might well be a caldera and at its edges are domes with features that suggest they were formed by the intrusion of high-viscosity silicic lava, a type of lava rare on the moon. Any model of the moon's thermal evolution must now be able to account for this volcanic province as well as the familiar mare.
“Most of the volcanic activity on the moon was basaltic,” said primary author Brad Joliff of Washington University to SPACE.com in an email. “Finding other volcanic types is interesting as it shows the geologic complexity and range of processes that operate on the moon, and how the moons volcanism changed with time.”
According to Joliff, the domes were likely formed by lava which came from within the moon that flowed up through cracks to pool just beneath the moon’s surface, which then pressed out to create them.
In 1998, NASA’s Lunar Prospector probe circled the moon’s surface revealing a highly reflective plain lying between two ancient impact craters which is now known as the Compton-Belkovich region.
The silicate rocks and thorium found in this region suggested a more involved type of volcanic activity similar to that which created the moons well-known dark plains of basaltic plains known as “maria”, or “seas.”
Image credit: F. Scholten, DLR. NASA/GSFC/ASU/WUSTL
Provided by The Daily Galaxy via NASA and wired.com
