Lunar rocks hint at recent volcanic activity
A researcher with the Institute of Geology and Geophysics, Chinese Academy of Sciences classifies micron-sized particles in lunar soil.
The first lunar rocks brought back to Earth in decades show the Moon was volcanically active more recently than previously thought, Chinese scientists said yesterday.
A Chinese spacecraft carried lunar rocks and soil to Earth last year – humanity's first mission in four decades to collect samples from the Moon, and a milestone for China's growing space program.
The samples included basalt – a form of cooled lava – from 2.03 billion years ago, scientists found, pushing the last known date of volcanic activity on the moon closer to the present day by as much as 900 million years.
Analysis of the samples "reveals that the Moon's interior was still evolving at around two billion years ago," the Chinese Academy of Sciences said in a statement.
Previous moon rocks brought back by US and Soviet missions showed evidence of lunar activity up to 2.8 billion years ago, but left a gap in scientists' knowledge about the more recent history of Earth's natural satellite as they were from older parts of the lunar surface.
The Chang'e-5 mission – named after a mythical moon goddess – collected 2kg of samples from a previously unexplored area of the moon called Mons Ruemker in the Oceanus Procellarum or "Ocean of Storms."
The area was selected as it was thought by scientists to be more recently formed, based on the lower density of craters from meteors on its surface.
"Altogether those results are extremely exciting, providing amazing science and results on understanding the lunar formation and evolution over time," Audrey Bouvier, a planetology professor at Germany's University of Bayreuth, said in a video message at a Beijing press conference yesterday.
The latest findings, published in three papers in the Nature journal yesterday, open up new questions for scientists trying to decipher the history of the Moon.
"How did the Moon sustain volcanic activity for so long? The Moon is naturally small and should disperse heat quickly, or so the thinking goes," CAS researcher Li Xianhua, one of the authors of the studies, told reporters.
"Volcanic activities are a very important thing on the moon. They show the vitality inside the moon, and represent the recycling of energy and matter inside the moon," Li told reporters.
