I started collecting moon rocks as an adjunct to the Apollo artifacts, and they are diverse and fascinating touchstones that help tell the history of the moon. From analyzing these meteorites and the Apollo samples and cross-referencing orbital survey data, we know when the Moon split off the Earth and when it had a convective magma ocean that explains the gravitational anomalies that make lunar orbit zesty and keep one side tidally locked to face the Earth, leaving the far side for Pink Floyd ballads.
The moon is a relatively unaltered time capsule going back 4.46 billion years, early in our solar system’s formation, back when a planet 10x the size of Earth was flung out of our solar system to be lost in space. It's rough out there when Jupiter throws its weight around in an orbital resonance. When you look up at it at night, all of those craters you see are from meteorite strikes, and some of those dislodged moon rocks with enough force to blast them away from the moon, and in some cases, all the way to Earth.
Clockwise from top left ring:
1)The largest central slice of Gadamis 004, one of the oldest rocks from the moon. This “lunar ferroan anorthosite, cataclastic” shows that the moon was covered with a magma ocean after being jettisoned from a massive collision of a Mars-sized planet with Earth, about 100M years after our solar system started. This ancient lunar meteorite is the closest match to the rocks collected on the Apollo 16 mission to the lunar highlands. From PSRD 2004: “the record of early events on Earth, Venus, and Mars has been obscured or erased by billions of years of geological activity. Processes such as convection, volcanism, weathering, and erosion have largely obliterated the primary signatures that would inform us about the mechanisms and timing of planetary formation in the inner Solar System. Fortunately, nature has provided a keystone that links the record of early nebular events preserved in meteorites with the subsequent geological evolution of the terrestrial planets, and that keystone is the Moon. For example, volcanism on the Earth and Moon overlapped in time for about a billion years, yet the Moon's crust is sufficiently old that it preserves direct evidence for planetary-scale events that occurred before the Earth's surface stabilized. In effect, the surface of the Moon is a time capsule that carries a record of the physical processes that created and modified the terrestrial planets. Lunar anorthosites in particular have assumed a key role in our understanding of the early history of the Moon because lunar geochemists think that these rocks crystallized directly from the global magma ocean. The pyroxenes and olivines from these rocks defined an age of 4.46 ± 0.04 billion years. This may represent a robust estimate for the primary crystallization age of the earliest lunar crust.” I gave a small slice of this moon rock to about 150 eclipse-viewing guests on Monday, a memento from our celestial sister.
2)Largest central slice of NWA 5000, the most beautiful moon rock to my eye. For several years, it was the largest known moon rock on Earth, larger than any brought back by Apollo. A massive impact event ~ 3.2 billion years ago created a giant melt sheet of a type of rock referred to as gabbro. The impacting body left exotic material in this Lunaite, solving the mystery of why there is metal embedded in the gabbro clasts, (something that was never observed before NWA 5000 was studied.) Another asteroid impact around 600 million years ago was mostly responsible for producing its distinctive brecciated matrix as well as bringing this rock to the surface of the Moon. This is where it was exposed to the solar wind, which implanted hydrogen-rich gas bubbles into the matrix. Then another asteroid strike ejected this rock from the Moon and created the cross-cutting, thin glass veins ~2000 years ago, and after hurtling through space and around the sun for over 1.3 thousand years, landed in the Western Sahara desert to be discovered in 2007. Only 0.1% of meteorites are from the moon, making them more rare than pure diamond on Earth. More: flic.kr/p/nfyFUv
3)Dark Side of the Moon — NWA 15583 is a singular stone from our moon, found in Algeria in 2022. It has been officially classified as "Lunar meteorite (feldspathic breccia)” Breccias are abundant on the moon, the pulverized agglomerations of rocks bombarded by ancient asteroid strikes. More: flic.kr/p/2pwRQYv
4)Another view of NWA 5000, a unique highlands monomict gabbroic breccia (meaning a type of rock mainly made of related fragments of gabbro). We know from remote observation and the Luna/Apollo missions that there are two main classes of rocks from the Moon. The first type is referred to as "mare" (meaning "sea"), pertaining to the darker areas of the Moon mainly composed of ancient (3 to 3.8 billion year old) basalt lava flows. The second type referred to as "highlands" pertains to the lighter colored areas of the Moon mainly composed of feldspar-rich anorthosite rocks. The Moon is believed to be about 4.5 billion years old and for about 600 million years during its early history was bombarded by pieces left over from formation of the planets. Impactors continued to strike the Moon at a decreasing rate, creating the heavily cratered surface of the lunar crust. During this time, melting of the deeper lunar mantle produced fluid basalt magma that erupted into the larger impact basins producing the dark areas of the the lunar surface ("maria").
5)Pure Lunar Gabbro, NWA 6950, one of only 10 every found (it’s the lightest color one, bottom right). This lunar meteorite has coarse mineral grains, which indicate it originally cooled slowly at depth. Research has determined the age of this meteorite to be 3.1 billion years old. More: flic.kr/p/2jgEJat
6)Rare Mare Basalt. The dark end cut. NEA 039. More to come on this one.
7)A huge 5.3kg unpaired whole stone. NWA 14747 is classified as Lunar (anorthositic gabbronoritic melt breccia). More: flic.kr/p/2n9bybJ
8)“Starry Night” (bottom left) NWA 13951. This large and beautiful end cut of feldspathic breccia has the natural beauty of the dark side, with interior and exterior revealed. The other half weighs 3 lbs., and is currently for sale here: www.rrauction.com/auctions/lot-detail/li/347777206914414
9)Lunar troctolite, with a glossy polish. More to come on this one, recently classified: NWA 16372
