The research suggests that lava associated with lunar fire fountains contained significant amounts of carbon.
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New analysis techniques used to study Moon rocks returned by Apollo astronauts in the early 1970s suggest Earth’s satellite experienced volcanic eruptions in its early days.
“The carbon is the [element] that is producing the large spectacle”, says Saal.
“The question for many years was what gas produced these sorts of eruptions on the Moon”, says Alberto Saal of Brown University, one of the authors of a study appearing in Nature Geoscience. The Apollo missions found remnants of these lava fountains in tiny beads of volcanic glass on the moon. Based on the changing concentrations of carbon and hydrogen, they adapted a model of how gases escape and found that the carbon combined with oxygen burst out first, causing the eruption, and then the hydrogen gas escaped afterward. The part that’s new-confirming that this activity was driven by carbon monoxide gas-gives astronomers new insight into how the moon formed.
The amount of carbon detected in the melt inclusions was found to be very similar to the amount of carbon found in basalts erupted at Earth’s mid-ocean ridges. Scientists from Brown University and the Carnegie Institution for Science announced this week (August 24, 2015) that they’ve identified the volatile gas that drove those eruptions. Melt inclusions are very fine crystals that contain gasses of volcanic magma.
“The lunar volcanic glasses are thought to be the product of fire-fountain eruptions, in which a jet of basaltic lava erupts through a vent, spattering droplets of lava that cool quickly to form glass”, he explained in the article.
‘Most of the carbon would have degassed deep under the surface, ‘ Saal said. Many such dark mantles can be seen on the lunar surface.
In fact, the molten magma was only discovered following the creation of a new probe technique reducing the detection limits of carbon by two orders of magnitude allowing for a measurement of as low as 0.1 part per million. Saal and colleagues posit that the Earth and the moon may have similar concentrations of water, which is shown by the amount of hydrogen particles present in the lunar samples.
Hauri added that Carnegie’s NanoSIMS is able to measure low levels of carbon about a diameter size of the human hair.
“OK, we have chlorine, sulfur and fluorine that, previously, people had demonstrated”, Saal said.
The result of study has implications for ongoing research about the origin of moon. Debris from the impact eventually coalesced into the Moon.
In addition to providing a potential answer to the lunar fire fountains mystery, the findings also serve as more evidence that some volatile reservoirs in the lunar interior share a common origin with reservoirs in the Earth.
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According to Saal, this finding suggests that either some of Earth’s volatile elements survived the impact that created the moon or that they both got volatile elements from the same source after formation, like meteorites.
