One of the theories of the origin of the Moon is Earth collided with a planet named Theia, which was approximately the size of Mars, and the debris of that collision eventually formed the Moon we see today.
A new study published in Science Advances provides significant evidence to support that theory as researchers analyzed fragments of a lunar meteorite. The meteorite was originally debris from a large asteroid impact into the lunar surface, and after analyzing the fragments, the researchers discovered noble gasses such as helium and neon trapped within the fragments, which match up with the same isotopes found in solar wind. However, the fragments were never exposed to solar wind.
The team noticed that the same isotope ratios found within the fragments were very similar to the isotope ratios of neon in Earth's mantle located deep within the surface. The similarity between the isotope ratios within the fragments and Earth's molten mantle that hasn't been disturbed since its early formation approximately 4.5 billion years ago has led researchers to believe the gases within the fragments came from Earth.
"While such gasses are not necessary for life, it would be interesting to know how some of these noble gasses survived the brutal and violent formation of the Moon. Such knowledge might help scientists in geochemistry and geophysics to create new models that show more generally how such most volatile elements can survive planet formation, in our solar system and beyond," said geochemist Henner Busemann of ETH Zurich.