Chang’e 6 lunar samples suggest early meteorite impacts brought water to Earth and Moon

The Chang’e-6 mission returned lunar samples from the Moon’s far side, which contain fragments of a rare type of meteorite that may have contributed water to both the Earth and the Moon.

According to Universe Today and Scientific American, researchers examined the material and identified minerals consistent with Carbonaceous Ivuna-type (CI) chondrites, a fragile type of meteorite rarely preserved on Earth.

Analysis of these samples indicates that they likely struck the Moon before the Nectarian Period, around 3.9 billion years ago, coinciding with the Late Heavy Bombardment when numerous asteroids impacted the inner Solar System.

Chang’e 6 lunar samples reveal meteorite impacts delivered water to Earth and Moon

Preservation of meteorite material on the Moon

Meteorites are a source of chemical information about their parent bodies, but research that relies on samples fetched from Earth is constrained by erosion, atmospheric filtration, and geological processes.

Where the Moon is concerned, the lack of atmosphere, wind, water erosion, and major geological activity means that meteorite impacts can be preserved more vividly.

The research team led by Professors Xu Yigang and Lin Mang at the Chinese Academy of Sciences, with collaborators from Brown University, Ritsumeikan University, and Vrije Universiteit Brussel, analyzed the Chang’e-6 samples and identified seven olivine-bearing minerals indicative of CI chondrites.

CI chondrites are defined by a high carbon content in the form of graphite, carbonates, and organic compounds, including amino acids.

Chemical and isotopic analysis

The team conducted textural characterization and triple oxygen isotope analysis on the lunar samples, confirming their origin as CI-like chondrites.

These meteorites likely arrived during the Late Heavy Bombardment, a period between 4.1 and 3.8 billion years ago when a large number of asteroids and comets impacted the inner Solar System.

The chemical composition of the samples shows that the CI chondrites carried water and organic molecules, consistent with previous findings from asteroid samples, such as those returned by NASA from Bennu.

The oxygen isotope ratios in the lunar fragments also match those of asteroids Ryugu and Bennu, confirming an extraterrestrial origin rather than a lunar mantle source, as reported by Scientific American.

Implications for water delivery to Earth and Moon

CI chondrites are known for their volatile content, including water and organic compounds.

Finding these pieces of meteorites on the Moon backs the idea that the asteroids that hit the Moon and Earth in the past eventually brought water and other gases to both bodies.

First off, scientists found that there was some water ices on the Moon. They also noticed that the isotopes of the ices were similar to those of CI chondrite material.

The Chang’e-6 findings suggest that CI chondrites played a significant role in shaping the volatile inventory of the Earth-Moon system.

The research was published in Proceedings of the National Academy of Sciences on October 20, and the way the samples were analyzed for their study can be used for any other m

The finding has been a surprise because the majority of the lunar samples that have been returned previously are from the near side of the Moon, which is less cratered and more geologically active.

Chang’e-6 accomplished its sampling from the South Pole–Aitken Basin, the largest and deepest crater on the Moon that contains the old impact materials.

The first detailed analysis of the iron, manganese, and zinc in the samples led to the conclusion that the samples came from meteorites rather than the lunar mantle.

According to Universe Today and Scientific American, the team will study the Chang’e-6 material to figure out the age and detailed chemical makeup of other fragments and thus have more evidence concerning the role of meteorite impacts in the early Solar System.