General consensus has put the last volcanic activity on the moon occurring between 1 and 1.5 billion years ago. That’s changing today. A recent discovery by NASA’s Lunar Reconnaissance Orbiter (LRO) is providing very strong evidence the moon’s volcanic activity saw a gradual slowdown. Not the abrupt halt around 1 billion years ago many researchers thought.
Many distinctive rock deposits have been estimated to be less than 100 million years ago. That means as the dinosaurs ruled the world, the moon was volcanically active. Some of these deposits may even be less than 50 million years old.
“This finding is the kind of science that is literally going to make geologists rewrite the textbooks about the moon,” said John Keller, LRO project scientist at NASA’s Goddard Space Flight Center.
Researchers from Arizona State University and Westfälische Wilhelms-Universität Münster in Germany led the research that was recently published in Nature Geoscience.
The team identified 70 small volcanic features on the near side of the moon. These features were a combination of smooth, low, rounded mounds near patches of rough terrain, and are referred to as ‘irregular mare patches.’
“Finding previously unknown geologic features on the lunar surface is extremely exciting,” said Sarah Braden, lead author, in a statement.
One particular feature that was observed again was Ina. This feature was actually first observed from lunar orbit by Apollo 15 astronauts back in the 70s. Studies then put the age of Ina at around 10 million years ago, but at the time, it was believed to be a one-of-a-kind feature. Images from the LRO’s two Narrow Angle Cameras showed dozens of similar volcanic features.
“The existence and young age of the irregular mare patches provides a new constraint for models of the lunar interior’s thermal evolution,” Braden says. “The lunar mantle had to remain hot enough for long enough to provide magma for the small-volume eruptions.”
Image credits: NASA/GSFC/Arizona State University