2.35 Billion-Year-Old Meteorite Discovered in Africa Contains Secrets to The Moon's Geology
A lunar meteorite is revealing some unknown secrets about the Moon's volcanic history. The meteorite, Northwest Africa 16286, was uncovered in Africa in 2023. Researchers estimate that it is the youngest basaltic lunar meteorite discovered on Earth. It represents a unique chemical signature, which could help experts understand what happened in the Moon's geology during the one-billion-year gap that is present in the insights undertaken by experts to date. New investigations and findings related to the lunar meteorite were discussed in detail during the Goldschmidt Conference in Prague.
Northwest Africa 16286
Further examinations indicate that the Northwest Africa 16286 is 2.35 billion years old and weighed around 311 grams. The meteorite stands apart from samples brought by missions, as the latter were extracted from specific locations around the mission sites, according to Earth. This specimen got knocked off from Moon due to an impact, and traveled through space to reach Earth. "Lunar rocks from sample return missions are fantastic in the insights they provide us, but they are limited to the immediate areas surrounding those mission landing sites," explained Dr. Joshua Snape, a research fellow at the University of Manchester. "By contrast, lunar meteorites can potentially be ejected by impact cratering occurring anywhere on the Moon's surface. As such, there's some serendipity surrounding this sample; it just happened to fall to Earth and reveals secrets about lunar geology without the massive expense of a space mission."
Features of the Meteorite
Analysis implied that the rock was not from the Moon's surface, but from deep inside it. It formed due to the hardening of erupted lava on the Moon. The rock was composed of potassium, titanium, and large crystals of olivine, a mineral found in volcanic boulders of Earth. Experts also investigated the meteorite's lead isotopes, which informed them that the portion from which the rock was broken apart had a high uranium-to-lead ratio. It occurs when the place has been hot for an extended time. Based on the age of rock, researchers believe that the Moon's interior was undergoing volcanic activity for longer than previously known. The team also believes that certain processes were being facilitated on the Moon, which encouraged the volcanic activity.
The Billion-Year Gap
If the assertion regarding volcanic activity is true, then researchers know what was happening in the billion years inside the Moon's surface, about which they have no readings. Currently, all knowledge about the Moon's geology comes from basalts collected by the Apollo, Luna, and Chang'e 6 missions and rocks gathered by China's Chang'e 5 mission. There is a one-billion-year gap between the insights brought by the two sets of samples. Northwest Africa 16286 was older than the samples brought by Apollo, Luna, and Chang'e 6 missions, but younger than the ones in China's Chang'e 5 mission. So, Northwest Africa 16286 gives a glimpse of the activities during that missing period.
The rock suggests that the Moon was active, and a heat generation process could be triggering the volcano underneath the surface over those billion years. This process could have involved radiogenic elements that decayed and then released heat over a long period. Researchers were ecstatic to find this 'missing' piece of information. "There is much more yet to learn about the Moon's geological past, and with further analysis to pinpoint its origin on the surface, this rock will guide where to land future sample return missions," added Snape.