Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mound near lunar south pole formed by unique volcanic process

16.10.2015

A giant mound near the Moon’s south pole appears to be a volcanic structure unlike any other found on the lunar surface, according to new research.

The formation, known as Mafic Mound, stands about 800 meters (2,600 feet) tall and 75 kilometers (47 miles) across, smack in the middle of a giant impact crater known as the South Pole-Aitken Basin. This new study suggests that the mound is the result of a unique kind of volcanic activity set in motion by the colossal impact that formed the basin.


The top image is the South Pole-Aitken basin taken by the Lunar Reconnaissance Orbiter’s Wide Angle Camera.

Credit: NASA/Goddard/Arizona State University

The lower image is from the Lunar Orbiter Laser Altimeter. Mafic Mound is the reddish splotch in the middle (Red is high ground, blue is low).

Credit: NASA/Goddard/MIT/Brown University

“If the scenarios that we lay out for its formation are correct, it could represent a totally new volcanic process that’s never been seen before,” said Daniel Moriarty, a Ph.D. student in Brown University’s Department of Earth, Environmental and Planetary Sciences and the study’s lead author.

The research has been accepted for publication in Geophysical Research Letters, a publication of the American Geophysical Union.

Mafic Mound (mafic is a term for rocks rich in minerals such as pyroxene and olivine) was first discovered in the 1990s by Carle Pieters, a planetary geologist at Brown and Moriarty’s adviser. What makes it curious, other than its substantial size, is the fact that it has a different mineralogical composition than the surrounding rock. The mound is rich in high-calcium pyroxene, whereas the surrounding rock is low-calcium.

“This unusual structure at the very center of the basin begs the question: What is this thing, and might it be related to the basin formation process?” Moriarty said.

To investigate that, Moriarty and Pieters looked at a rich suite of data from multiple lunar exploration missions. They used detailed mineralogical data from the Moon Mineralogy Mapper, which flew aboard India’s Chandrayaan-1 spacecraft. NASA’s Lunar Orbiter Laser Altimeter provided precise topographic data, and data from the GRAIL mission characterized gravitational anomalies in the region.

Those combined datasets suggested that Mafic Mound was created by one of two unique volcanic processes set in motion by the giant South Pole-Aitken impact. An impact of that size would have created a cauldron of melted rock as much as 50 kilometers (30 miles) deep, some researchers think. As that sheet of impact melt cooled and crystalized, it would have shrunk. As it did, still-molten material in the middle of the melt sheet may have been squeezed out the top like toothpaste from a tube. Eventually, that erupted material may have formed the mound.

Such a process could explain the mound’s strange mineralogy. Models of how the South Pole-Aitken melt sheet may have crystalized suggest that the erupting material should be rich in high-calcium pyroxene, which is consistent with the observed mineralogy of the mound.

Another scenario that fits the data involves possible melting of the Moon’s mantle shortly after the South Pole-Aitken impact. The impact would have blasted tons of rock out of the basin, creating a low-gravity region. The lower gravity condition could have enabled the center of the basin to rebound upward. Such upward movement would have caused partial melting of mantle material, which could have erupted to form the mound.

These scenarios make for a strong fit to those very detailed datasets, Moriarty said. And if either is true, it would represent a unique process on lunar surface. Moriarty said a sample return mission to the South Pole Aitken Basin would be a great way to try to verify the results. The basin has long been an interesting mission target for lunar scientists.

“It’s the largest confirmed impact structure in the solar system and has shaped many aspects of the evolution of the Moon,” Moriarty said. “So a big topic in lunar science is studying this basin and the effects it had on the geology of the Moon through time.”

A sample return mission to the basin could bring back bits of lunar mantle, the composition of which is still not fully understood. A returned sample could also put a firm date on when the impact occurred, which could be used as a standard to date other features on the surface.

And in light of this work, a sample could also help to shed light on a unique lunar volcanic process.

###

The American Geophysical Union is dedicated to advancing the Earth and space sciences for the benefit of humanity through its scholarly publications, conferences, and outreach programs. AGU is a not-for-profit, professional, scientific organization representing more than 60,000 members in 139 countries. Join the conversation on Facebook, Twitter, YouTube, and our other social media channels.

Notes for Journalists
Journalists and public information officers (PIOs) of educational and scientific institutions who have registered with AGU can download a PDF copy of the article by clicking on this link: http://onlinelibrary.wiley.com/doi/10.1002/2015GL065718/full

Or, you may order a copy of the final paper by emailing your request to Lauren Lipuma at llipuma@agu.org.

Please provide your name, the name of your publication, and your phone number.

Neither the paper nor this press release is under embargo.
Title
“The nature and origin of Mafic Mound in the South Pole-Aitken Basin”

Authors:
Daniel Moriarty: Brown University Department of Earth, Environmental and Planetary Sciences, Providence, Rhode Island, USA.

Carle M. Pieters: Brown University Department of Earth, Environmental and Planetary Sciences, Providence, Rhode Island, USA.

Contact Information for the Authors:
Daniel Moriarty: daniel_moriarty@brown.edu


AGU Contact:
Lauren Lipuma
+1 (202) 777-7396
llipuma@agu.org

Brown University Contact:
Kevin Stacey
+1 (401) 863-3766
kevin_stacey@brown.edu

Lauren Lipuma | AGU American Geophysical Union
Further information:
http://news.agu.org/press-release/mound-near-lunar-south-pole-formed-by-unique-volcanic-process/

Further reports about: American Geophysical Union Earth NASA lunar south pole lunar surface

More articles from Earth Sciences:

nachricht Climate satellite: Tracking methane with robust laser technology
22.06.2017 | Fraunhofer-Gesellschaft

nachricht How reliable are shells as climate archives?
21.06.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>