[Rockhounds] Moon rocks found in Antarctica include tiny amounts of gas that may have come from Earth

[Kreigh Tomaszewski]

Moon rocks aren't just about the rock — the gas trapped inside is just as
intriguing.

A new examination of six lunar meteorites found in Antarctica has revealed
the first definitive proof that the moon inherited chemical elements from
Earth's interior. The discovery adds support to the theory that our
planet's most enduring companion was born when something massive slammed
into the Earth in the distant past, also known as the giant impact theory.

During doctoral research at ETH Zurich in Switzerland, Patrizia Will
discovered traces of helium and neon — both noble gases, which rarely bond
to other elements — in six lunar meteorites from NASA's Antarctic
collection.

The meteorites are composed of volcanic rock called basalt that formed as
magma welled up from the interior of the moon then rapidly cooled. This
cooling process created lunar glass particles within the samples that
retain chemical signatures of solar gases. After the basalt formed,
additional layers of rock enveloped it, protecting the glass from charged
particles, both those from the sun's constant stream of solar wind and
those from beyond the solar system, dubbed cosmic rays. The isolation
preserved this fingerprint and guaranteed the origin of the gases trapped
inside, the researchers reasoned.

Scientists were able to catch the fingerprints of helium and neon in the
meteorites thanks to a particularly sensitive noble gas mass spectrometer
that researchers nicknamed Tom Dooley after a Grateful Dead song. (Mass
spectrometers sort out by weight elements within a sample.)

"Finding solar gases, for the first time, in basaltic materials from the
moon that are unrelated to any exposure on the lunar surface was such an
exciting result," Will said in a statement.

 https://www.space.com/moon-meteorites-noble-gases-from-earth