That may help us understand how the Moon formed, say researchers. Yes, that seems odd, but the we know surprisingly little about how the Moon—which plays a very important role in enabling life on Earth—was formed:
One of the most important scientific outcomes of the Apollo program was giving scientists the opportunity to explain our Moon’s origins.
Geochemical analysis of the Apollo lunar samples suggested that our Moon was formed 4.5 billion years ago, when a Mars-sized body known as Theia hit Earth when our planet had almost completely formed. Computer models indicate that in this “big splat,” most of the material that ended up forming the Moon—between 70% and 90% of the satellite’s composition—came from Theia.
Although most planetary scientists think the giant impact actually happened, evidence of Theia has been hard to find. Lab measurements of the isotopic ratios of multiple elements such as oxygen have found that Earth and the Moon are virtually indistinguishable. They couldn’t find a trace of Theia’s chemical signature.
This conundrum left researchers with just two likely explanations. On the one hand, Theia might have had the same exact isotopic composition as Earth. This idea does not bode well for current theories about the formation of the solar system and is largely ruled out. On the other hand, the impact could have been so powerful that it caused a thorough mixing of Earth’s and Theia’s material or was at least able to hide its results from our current array of instruments…
Now a group of researchers has finally detected oxygen isotope differences between terrestrial and lunar rocks, something that could ease constraints when creating lunar formation models and rule out some of the most extreme scenarios. Javier Barbuzano, “Earth Rocks and Moon Rocks Are More Different Than We Thought” at Eos
We still don’t know a whole lot: Hugh Ross: The fine-tuning that enabled our life-friendly moon creates discomfort Was it yesterday that we noted particle physicist Sabine Hossenfelder’s view that fine-tuning is “a waste of time”? Not so fast. If the evidence points to fine-tuning and the only alternative is the crackpot cosmology she deplores, it’s not so much a waste of time as a philosophically unacceptable conclusion. Put another way, it comes down to fine-tuning, nonsense, or nothing.
Moon formed from smashed moonlets?
Scientists finally know how old Moon is What’s surprising, really, is how little we know about the moon in general.
And various current theories:
Another moon origin theory: Epic crash
How the Moon Formed: 5 Wild Lunar Theories (Mike Wall at Space.com, 2014)
Our moon formed in collision with embryo planet?
and
Origin of the moon still shrouded in mystery