Chinese scientists discover new lunar minerals from Chang'e-5 samples

Chinese scientists have discovered two new lunar minerals through research on samples retrieved by China's Chang'e-5 mission, the China National Space Administration (CNSA) announced Friday.

Of the two, Magnesiochangesite-(Y) is a magnesium-rich member related to China's earlier discovery Changesite-(Y), while Changesite-(Ce) is a new lunar mineral species characterized by the cerium-dominance analogue of Changesite-(Y).

The discoveries bring the total number of lunar minerals identified by Chinese scientists to four. Worldwide, 11 lunar minerals have been discovered both in the return samples and lunar meteorites since the 1970s.

Chinese scientists behind the new findings were working with just milligrams of lunar soil samples.

Out of the hundreds of thousands of tiny grains on one epoxy mount, scientists singled out special grains that could hold evidence of a new mineral. The grains are only a few micrometers across, or about one-third to one-thirtieth the thickness of a human hair.

Scientists then zoom in with more precise tests, including chemical analysis, spectroscopy, and crystal structure determination.

New lunar mineral findings shed new light on the moon and the Earth

The team that discovered Magnesiochangesite-(Y) also found Changesite-(Y) in 2022.

"The new minerals mean new members to the lunar mineral database," Ge Xiangkun, deputy director of the Analytical Laboratory at Beijing Research Institute of Uranium Geology told CGTN. "The new discoveries have also strengthened our technical capabilities and demonstrated our country's scientific research capacity."

The team that found Changesite-(Ce) from Chang'e-5 samples had recently identified another lunar mineral, the Magnesiochangesite-(Ce).

China's slew of new lunar mineral findings could shed new light on the moon and the Earth.

"This is very important for understanding the lunar material makeup and composition, and for understanding the moon's formation and evolution," said Hou Zengqian, academician at Chinese Academy of Sciences and director of China's National Key Laboratory of Deep Earth Exploration and Mineral Prospecting. "It also provides valuable reference for our understanding on Earth of how rare earth elements migrate, become enriched, differentiate, and form mineral deposits."

Hou said the team will continue studying the samples to learn more about the moon's composition, formation and evolution.

"We also aim to further broaden our knowledge and understanding of how planets in the galaxy form and evolve, while providing a scientific basis for future resource development and utilization," he added.

Discoveries 'not random'

Wang Yanjuan from the Chinese Academy of Geological Sciences was the first to discover Changesite-(Ce) and Magnesiochangesite-(Ce), both named this year.

She said the discoveries are not random, citing clear research goals, and having the technical expertise that helps the team identify new minerals.

But the team is lucky to have samples brought back by the Chang'e missions. "That access makes systematic, long-term, repeatable research possible.”

China's Chang'e-6 mission collected 1,935.3 grams of samples from the far side of the moon – the first time in human history. The earlier Chang'e-5 mission retrieved 1,731 grams of lunar samples.