Drier lunar far side offers insight on moon's evolution: Chinese study

The latest discovery from rock samples returned by China's Chang'e-6 lunar mission reveals that the moon's mantle contains less water on the far side compared to the near side, suggesting that the "hidden hemisphere," which always faces away from Earth, tends to be much drier.

Published in the journal Nature on Wednesday, a new study by Chinese scientists found that the water content in each gram of the thick rocky layer beneath the moon's far side surface is less than 2 micrograms, the lowest record ever reported.

Previous studies on samples from the lunar near side have shown that the water concentrations within the moon's interior could reach up to 200 micrograms per gram.

"Currently, we have measured the water content in the basaltic mantle source region of Chang'e 6, and it is approximately less than 2 micrograms per gram. The result we have obtained from the near side of the moon is around 7.5 micrograms per gram. This means that the water content in the mantle on the far side of the moon is even lower than that on the near side," said Hu Sen, a research fellow from the Institute of Geology and Geophysics of the Chinese Academy of Sciences.

The global scientific community widely believes that the moon was formed when a Mars-sized object collided with Earth 4.5 billion years ago. During this extremely hot impact event, the moon was thought to be depleted of water and other volatile elements.

Over the past two decades, there has been debate about whether the water content in the moon's mantle, the middle layer between its surface and its core, is abundant or scarce, and all the published estimates were derived from the near side samples of the moon.

The Chang'e-6 lunar probe, launched in early May 2024, landed in the moon's South Pole-Aitken Basin and returned to Earth in late June with more than 1,935 grams of the first-ever samples from the less-known far side of the moon.

The moon samples used in this study weigh 5 grams, consisting of 578 particles ranging in size from 0.1 to 1.5 millimeters. These particles were carefully sieved and hand-selected, with 28 percent of them being mare basalt fragments.

The newly found disparity in the moon's internal water content is of great significance, which may offer a fresh insight into the moon's formation and evolution.

"The water on the moon we are talking about is mostly water from the moon's interior, which is related to the processes of its origin, evolution, and formation. Our country's Chang'e 7 mission will focus on issues related to lunar surface water in the future," said Hu.

The findings of this study also hold significant implications for future lunar exploration tasks, as water on the moon is key to long-term human settlement.

Drier lunar far side offers insight on moon's evolution: Chinese study

Drier lunar far side offers insight on moon's evolution: Chinese study

Uganda on Thursday announced the temporary suspension of flights to and from the neighboring Democratic Republic of the Congo (DRC) following an outbreak of Ebola Bundibugyo virus disease that has killed dozens of people.

Diana Atwine, permanent secretary at the Ministry of Health, said in a statement issued in Kampala that the National Task Force (NTF), chaired by Uganda's Vice President Jessica Alupo, had resolved to suspend all flights between Uganda and the DRC, with the measure taking effect within 48 hours.

The move follows the detection last week of two imported Ebola cases in Kampala, the Ugandan capital.

A 59-year-old Congolese man died from the virus at Kibuli Muslim Hospital in Kampala, while the other patient remains in isolation at Mulago National Referral Hospital. A total of 127 contacts have been identified and are in institutional quarantine.

According to Atwine, the government has also temporarily suspended public passenger ferry services on the Semuliki River, cross-border bus operations and all public passenger transport between Uganda and the DRC for the next four weeks, while allowing the continued movement of goods and food supplies.

According to the ministry, weekly markets in border sub-counties across high-risk districts have also been suspended for four weeks.

The NTF has activated a series of preparedness and response measures, including the suspension of cultural celebrations and commemorative events that draw large crowds along the Uganda-DRC border.

Over the past 24 hours, health authorities in the DRC and the World Health Organization have reported a worsening outbreak across the central African nation, with around 600 suspected cases and 139 probable deaths recorded since the outbreak was officially declared on May 15.

Uganda suspends DRC flights amid efforts to prevent Ebola outbreak spillover