Research reveals possibly active tectonic system on the moon

Related Articles

Related Articles

Researchers have discovered a system of ridges spread across the nearside of the Moon topped with freshly exposed boulders.

The ridges could be evidence of active lunar tectonic processes, the researchers say, possibly the echo of a long-ago impact that nearly tore the Moon apart.

“There’s this assumption that the Moon is long dead, but we keep finding that that’s not the case,” said Peter Schultz, a professor in Brown University’s Department of Earth, Environmental and Planetary Sciences and co-author of the research, which is published in the journal Geology. “From this paper it appears that the Moon may still be creaking and cracking — potentially in the present day — and we can see the evidence on these ridges.”

 

Most of the Moon’s surface is covered by regolith, a powdery blanket of ground-up rock created by the constant bombardment of tiny meteorites and other impactors. Areas free of regolith where the Moon’s bedrock is exposed are vanishingly rare. But Adomas Valantinas, a graduate student at the University of Bern who led the research while a visiting scholar at Brown, used data from NASA’s Lunar Reconnaissance Orbiter (LRO) to spot strange bare spots within and surrounding the lunar maria, the large dark patches on the Moon’s nearside.

“Exposed blocks on the surface have a relatively short lifetime because the regolith buildup is happening constantly,” Schultz said. “So when we see them, there needs to be some explanation for how and why they were exposed in certain locations.”

For the study, Valantinas used the LRO’s Diviner instrument, which measures the temperature of the lunar surface. Just as concrete-covered cities on Earth retain more heat than the countryside, exposed bedrock and blocky surfaces on the Moon stays warmer through the lunar night than regolith-covered surfaces. Using nighttime observations from Diviner, Valantinas turned up more than 500 patches of exposed bedrock on narrow ridges following a pattern across the lunar nearside maria.

A few ridges topped with exposed bedrock had been seen before, Schultz says. But those ridges were on the edges of ancient lava-filled impact basins and could be explained by continued sagging in response to weight caused by the lava fill. But this new study discovered that the most active ridges are related to a mysterious system of tectonic features (ridges and faults) on the lunar nearside, unrelated to both lava-filled basins and other young faults that crisscross the highlands.

Infrared (upper left) and other images from NASA’s Lunar Reconnaissance Orbiter revealed strange bare spots where the Moon’s ubiquitous dust is missing. The spots suggest an active tectonic process. Credit : NASA

“The distribution that we found here begs for a different explanation,” Schultz said.

Valantinas and Schultz mapped out all of the exposures revealed in the Diviner data and found an interesting correlation. In 2014, NASA’s GRAIL mission found a network of ancient cracks in the Moon’s crust. Those cracks became channels through which magma flowed to the Moon’s surface to form deep intrusions. Valantinas and Schultz showed that the blocky ridges seemed to line up just about perfectly with the deep intrusions revealed by GRAIL.

“It’s almost a one-to-one correlation,” Schultz said. “That makes us think that what we’re seeing is an ongoing process driven by things happening in the Moon’s interior.”

Schultz and Valantinas suggest that the ridges above these ancient intrusions arestill heaving upward. The upward movement breaks the surface and enables regolith to drain into cracks and voids, leaving the blocks exposed. Because bare spots on the Moon get covered over fairly quickly, this cracking must be quite recent, possibly even ongoing today. They refer to what they’ve found as ANTS, for Active Nearside Tectonic System.

The researchers believe that the ANTS was actually set in motion billions of years ago with a giant impact on the Moon’s farside. In previous studies, Schultz and a co-worker proposed this impact, which formed the 1500-mile South Pole Aitken Basin, shattered the interior on the opposite side, the nearside facing the Earth. Magma then filled these cracks and controlled the pattern of dikes detected in the GRAIL mission. The blocky ridges comprising the ANTS now trace the continuing adjustments along these ancient weaknesses.

“This looks like the ridges responded to something that happened 4.3 billion years ago,” Schultz said. “Giant impacts have long lasting effects. The Moon has a long memory. What we’re seeing on the surface today is testimony to its long memory and secrets it still holds.”

BROWN UNIVERSITY

Header Image – Public Domain

Download the HeritageDaily mobile application on iOS and Android

More on this topic

LATEST NEWS

Walking, Talking and Showing Off – a History of Roman Gardens

In ancient Rome, you could tell a lot about a person from the look of their garden. Ancient gardens were spaces used for many activities, such as dining, intellectual practice, and religious rituals.

Curious Kids: How did the First Person Evolve?

We know humans haven’t always been around. After all, we wouldn’t have survived alongside meat-eating dinosaurs like Tyrannosaurus rex.

Ring-like Structure on Ganymede May Have Been Caused by a Violent Impact

Researchers from Kobe University and the National Institute of Technology, Oshima College have conducted a detailed reanalysis of image data from Voyager 1, 2 and Galileo spacecraft in order to investigate the orientation and distribution of the ancient tectonic troughs found on Jupiter’s moon Ganymede.

Tracing Evolution From Embryo to Baby Star

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) took a census of stellar eggs in the constellation Taurus and revealed their evolution state.

“Woodhenge” Discovered in the Iberian Peninsula

Archaeologists conducting research in the Perdigões complex in the Évora district of the Iberian Peninsula has uncovered a “Woodhenge” monument.

New Fossil Discovery Shows How Ancient ‘Hell Ants’ Hunted With Headgear

Researchers from New Jersey Institute of Technology (NJIT), Chinese Academy of Sciences and University of Rennes in France have unveiled a stunning 99-million-year-old fossil pristinely preserving an enigmatic insect predator from the Cretaceous Period -- a 'hell ant' (haidomyrmecine) -- as it embraced its unsuspecting final victim, an extinct relative of the cockroach known as Caputoraptor elegans.

New Algorithm Suggests That Early Humans and Related Species Interbred Early and Often

A new analysis of ancient genomes suggests that different branches of the human family tree interbred multiple times, and that some humans carry DNA from an archaic, unknown ancestor.

Long Neck Helped Reptile Hunt Underwater

Its neck was three times as long as its torso, but had only 13 extremely elongated vertebrae: Tanystropheus, a bizarre giraffe-necked reptile which lived 242 million years ago, is a paleontological absurdity.

Popular stories

Port Royal – The Sodom of the New World

Port Royal, originally named Cagway was an English harbour town and base of operations for buccaneers and privateers (pirates) until the great earthquake of 1692.

Matthew Hopkins – The Real Witch-Hunter

Matthew Hopkins was an infamous witch-hunter during the 17th century, who published “The Discovery of Witches” in 1647, and whose witch-hunting methods were applied during the notorious Salem Witch Trials in colonial Massachusetts.

Did Corn Fuel Cahokia’s Rise?

A new study suggests that corn was the staple subsistence crop that allowed the pre-Columbian city of Cahokia to rise to prominence and flourish for nearly 300 years.

The Real Dracula?

“Dracula”, published in 1897 by the Irish Author Bram Stoker, introduced audiences to the infamous Count and his dark world of sired vampiric minions.