Rusty lunar rock sample 66095 suggests that Moon's interior is dry

The Moon’s interior is likely “dry,” according to a new study by researchers from the Scripps Institution of Oceanography at the University Of California San Diego (UCSD) in the US. The researchers reached the conclusion after analyzing the rusty rock, named 66095, that was brought to Earth from Moon during Apollo 16 mission in 1972.

This study was funded by the NASA Emerging Worlds program and its detailed results have been published in the Proceedings of the National Academy of Sciences.

Whether Moon is dry or wet is an important question

Water is one of the vital ingredients of rust, and therefore rust on the outer surface of the lunar rock was suggestive of the presence of water on the surface or interior of Moon.

According to scientists, the question of Moon being dry or wet is important because it could provide clues about how this natural satellite of Earth was formed in our solar system billions of years ago.

According to James Day, from UCSD, the idea of the Moon being dry is consistent with the theory that Moon was formed after the occurrence of some cataclysmic impact event.

When rusty rock from Moon was first analyzed, some scientists speculated presence of water on the surface of Moon millions of years. Detailed tests of the rock, however, revealed that this rock and its rust were lunar in origin.

Chemical analysis of the rusty rock

According to this study, Moon was "very, very, hot," initially after it was formed—like an “an ocean of magma." It was so hot that any water or other volatile elements/compounds on it evaporated very early.

The team arrived at this conclusion after carrying out a chemical analysis of the rusty rock. The rust on this rock was found to contain a large amount of lighter isotopes of zinc. Because zinc is a volatile element, researchers believe it would have evaporated during the initial sweltering period of Moon, and later condensed on the surface.

These findings, however, run contrary to the results of a recently published study that suggested that Moon’s interior is actually wet. In that study, scientists analyzed glass deposits found on the surface of Moon and found the presence of water molecules in these deposits. This study was carried out by researchers from the Brown University.

James Day is however not much convinced with the results of that study and thinks that this study doesn’t explain how the glass bead deposits were formed on the lunar surface. Day says he wants to carry out further investigations on the glass bead deposits on the lunar surface to “solve this problem.”