New evidence shows giant meteorite impacts formed parts of the Moon's crust

May 11, 2020

TORONTO, CANADA (May 11, 2020) - New research published today in the journal Nature Astronomy reveals a type of destructive event most often associated with disaster movies and dinosaur extinction may have also contributed to the formation of the Moon's surface.

A group of international scientists led by the Royal Ontario Museum has discovered that the formation of ancient rocks on the Moon may be directly linked to large-scale meteorite impacts.

The scientists conducted new research of a unique rock collected by NASA astronauts during the 1972 Apollo 17 mission to the Moon. They found it contains mineralogical evidence that it formed at incredibly high temperatures (in excess of 2300 °C/ 4300 °F) that can only be achieved by the melting of the outer layer of a planet in a large impact event.

In the rock, the researchers discovered the former presence of cubic zirconia, a mineral phase often used as a substitute for diamond in jewellery. The phase would only form in rocks heated to above 2300 °C, and though it has since reverted to a more stable phase (the mineral known as baddeleyite), the crystal retains distinctive evidence of a high-temperature structure. An interactive image of the complex crystal used in the study can be seen here using the Virtual Microscope.

While looking at the structure of the crystal, the researchers also measured the age of the grain, which reveals the baddeleyite formed over 4.3 billion years ago. It was concluded that the high-temperature cubic zirconia phase must have formed before this time, suggesting that large impacts were critically important to forming new rocks on the early Moon.

Fifty years ago, when the first samples were brought back from the surface of the Moon, lunar scientists raised questions about how lunar crustal rocks formed. Even today, a key question remains unanswered: how did the outer and inner layers of the Moon mix after the Moon formed? This new research suggests that large impacts over 4 billion years ago could have driven this mixing, producing the complex range of rocks seen on the surface of the Moon today.

"Rocks on Earth are constantly being recycled, but the Moon doesn't exhibit plate tectonics or volcanism, allowing older rocks to be preserved," explains Dr. Lee White, Hatch Postdoctoral Fellow at the ROM. "By studying the Moon, we can better understand the earliest history of our planet. If large, super-heated impacts were creating rocks on the Moon, the same process was probably happening here on Earth".

"By first looking at this rock, I was amazed by how differently the minerals look compared to other Apollo 17 samples," says Dr. Ana Cernok, Hatch Postdoctoral Fellow at the ROM and co-author of the study. "Although smaller than a millimetre, the baddeleyite grain that caught our attention was the largest one I have ever seen in Apollo samples. This small grain is still holding the evidence for formation of an impact basin that was hundreds of kilometres in diameter. This is significant, because we do not see any evidence of these old impacts on Earth."

Dr. James Darling, a reader at the University of Portsmouth and co-author of the study, says the findings completely change scientists' understanding of the samples collected during the Apollo missions, and, in effect, the geology of the Moon. "These unimaginably violent meteorite impacts helped to build the lunar crust, not only destroy it," he says.
-end-
ROM Contact:

Kim Tait
Teck Endowed Chair of Mineralogy
Royal Ontario Museum (ROM)
ktait@rom.on.ca
289-838-2730

ABOUT THE ROM

Opened in 1914, the Royal Ontario Museum showcases art, culture and nature from around the world and across the ages. Among the top 10 cultural institutions in North America, Canada's largest and most comprehensive museum is home to a world-class collection of 13 million art objects and natural history specimens, featured in 40 gallery and exhibition spaces. As the country's preeminent field research institute and an international leader in new and original findings, the ROM plays a vital role in advancing our understanding of the artistic, cultural and natural world. Combining its original heritage architecture with the contemporary Daniel Libeskind-designed Michael Lee-Chin Crystal, the ROM serves as a national landmark, and a dynamic cultural destination in the heart of Toronto for all to enjoy.

Royal Ontario Museum

Related Moon Articles from Brightsurf:

New mineral discovered in moon meteorite
The high-pressure mineral Donwilhelmsite, recently discovered in the lunar meteorite Oued Awlitis 001 from Apollo missions, is important for understanding the inner structure of the earth.

First measurements of radiation levels on the moon
In the current issue (25 September) of the prestigious journal Science Advances, Chinese and German scientists report for the first time on time-resolved measurements of the radiation on the moon.

Researchers develop dustbuster for the moon
A team led by the University of Colorado Boulder is pioneering a new solution to the problem of spring cleaning on the moon: Why not zap away the grime using a beam of electrons?

First global map of rockfalls on the Moon
A research team from ETH Zurich and the Max Planck Institute for Solar System Research in Göttingen counted over 136,000 rockfalls on the moon caused by asteroid impacts.

Going nuclear on the moon and Mars
It might sound like science fiction, but scientists are preparing to build colonies on the moon and, eventually, Mars.

Astronaut urine to build moon bases
The modules that the major space agencies plan to erect on the Moon could incorporate an element contributed by the human colonizers themselves: the urea in their pee.

How moon jellyfish get about
With their translucent bells, moon jellyfish (Aurelia aurita) move around the oceans in a very efficient way.

Does crime increase when the moon is full?
Noting that anecdotal beliefs can affect public policies and practices, a 'pracademics' team from NYU's Marron Institute of Urban Management worked with public safety personnel to examine the commonly held axiom that crime rises with the full moon -- and found that the evidence is just not there.

Soil on moon and Mars likely to support crops
Researchers at Wageningen University & Research in the Netherlands have produced crops in Mars and moon soil simulant developed by NASA.

Are we prepared for a new era of field geology on the moon and beyond?
Space agencies must invest more resources on field geology training of astronauts to take full advantage of scientific opportunities on the moon and other planetary bodies, Kip Hodges and Harrison Schmitt urge, in an Editorial.

Read More: Moon News and Moon Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.