Subscribe free to our newsletters via your
  Moon News  


Subscribe free to our newsletters via your




















MOON DAILY
Ancient Polar Ice Reveals Tilting of Earth's Moon
by Staff Writers
Moffett Field CA (SPX) Mar 24, 2016


This polar hydrogen map of the moon's northern and southern hemispheres identifies the location of the moon's ancient and present day poles. In the image, the lighter areas show higher concentrations of hydrogen and the darker areas show lower concentrations. Image courtesy James Keane, University of Arizona; Richard Miller, University of Alabama at Huntsville. For a larger version of this image please go here.

New NASA-funded research provides evidence that the spin axis of Earth's moon shifted by about five degrees roughly three billion years ago. The evidence of this motion is recorded in the distribution of ancient lunar ice, evidence of delivery of water to the early solar system.

"The same face of the moon has not always pointed towards Earth," said Matthew Siegler of the Planetary Science Institute in Tucson, Arizona, lead author of a paper in Nature. "As the axis moved, so did the face of the 'man in the moon.' He sort of turned his nose up at the Earth."

Water ice can exist on Earth's moon in areas of permanent shadow. If ice on the moon is exposed to direct sunlight it evaporates into space. Authors of the Nature article show evidence that a shift of the lunar spin axis billions of years ago enabled sunlight to creep into areas that were once shadowed and likely previously contained ice.

The researchers found that the ice that survived this shift effectively "paints" a path along which the axis moved. They matched the path with models predicting where the ice could remain stable and inferred the moon's axis had moved by approximately five degrees. This is the first physical evidence that the moon underwent such a dramatic change in orientation and implies that much of the polar ice on the moon is billions of years old.

"The new findings are a compelling view of the moon's dynamic past," said Dr. Yvonne Pendleton, director of SSERVI, which supports lunar and planetary science research to advance human exploration of the solar system through scientific discovery.

"It is wonderful to see the results of several missions pointing to these insights."

The authors analyzed data from several NASA missions, including Lunar Prospector, Lunar Reconnaissance Orbiter (LRO), Lunar Crater and Observation Sensing Satellite (LCROSS), and the Gravity Recovery and Interior Laboratory (GRAIL), to build the case for a change in the moon's orientation. Topography from the Lunar Orbiter Laser Altimeter (LOLA) and thermal measurements from the Diviner lunar radiometer - both on LRO - are used to aid the interpretation of Lunar Prospector neutron data that support the polar wander hypothesis.

Siegler noticed that the distribution of ice observed at each of the lunar poles appeared to be more related to each other than previously thought. Upon further investigation, Siegler - and co-author Richard Miller of the University of Alabama at Huntsville - discovered that ice concentrations were displaced from each pole by the same distance, but in exactly opposite directions, suggesting the spin axis in the past was tilted from what we see today.

A change in the tilt means that some of the ice deposited long ago has since evaporated as it was exposed to sunlight, but those areas that remain in permanent shadow between the old orientation and the new one retain their ice, and thus indicate what happened.

A planetary body can shift on its axis when there is a very large change in mass distribution. Co-author James Keane, of the University of Arizona in Tucson, modeled the way changes in the lunar interior would have affected the moon's spin and tilt.

In doing so, he found the Procellarum region on the lunar near-side was the only feature that could match the direction and amount of change in the axis indicated by the ice distributions near the poles.

Furthermore, concentrations of radioactive material in the Procellarum region are sufficient to have heated a portion of the lunar mantle, causing a density change significant enough to reorient the moon.

Some of this heated mantle material melted and came to the surface to form the visible dark patches that fill large lunar basins known as mare. It's these mare patches that give the man in the moon his "face."

Siegler, Miller, and co-author David Lawrence of Johns Hopkins Applied Physics Laboratory in Laurel, Maryland are part of the Volatiles, Regolith and Thermal Investigations Consortium for Exploration and Science team, one of nine teams funded by SSERVI.

Said Siegler, "These findings may open the door to further discoveries on the interior evolution of the moon, as well as the origin of water on the moon and early Earth."

This interdisciplinary research was conducted across multiple institutions as part of NASA's Solar System Exploration Research Virtual Institute (SSERVI) based at NASA's Ames Research Center in Silicon Valley, California.

.


Related Links
Solar System Exploration Research Virtual Institute at NASA
Mars News and Information at MarsDaily.com
Lunar Dreams and more






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
MOON DAILY
Permanent Lunar Colony Possible in 10 Years
Moscow (Sputnik) Mar 15, 2016
Living on the Moon may become a reality sooner than anticipated as astrophysicists have assessed that a permanent lunar base is logistically feasible for humans - and could be built in less than a decade. Scientific papers released after a 2014 high-profile astronomical workshop suggest that a fully operational base could be constructed by 2022. The base would be a breakthrough for space e ... read more


MOON DAILY
New Gravity Map Gives Best View Yet Inside Mars

ExoMars performing flawlessly

Opportunity Rover Goes Back Downhill

ExoMars probe imaged en route to Mars

MOON DAILY
The Saturnian Sisters

The Tilted Terminator Of Enceladus

New photos show 'magic island' on Saturn's moon

Tethys, Janus pose with Saturn's rings in new NASA photo

MOON DAILY
More surprises in store for the New Horizons spacecraft?

Five papers provide new data from flyby of Pluto

Dust counter got few 'hits' on Pluto flyby

Pluto's 'Snakeskin' Terrain: Cradle of the Solar System?

MOON DAILY
Earth's moon wandered off axis billions of years ago

Permanent Lunar Colony Possible in 10 Years

China to use data relay satellite to explore dark side of moon

NASA May Return to Moon, But Only After Cutting Off ISS

MOON DAILY
New research shows how nanowires can be formed

ASRC professor leads study on reconfigurable magnetic nanopatterns

Atomic vibrations in nanomaterials

NIST invents fleet and fast test for nanomanufacturing quality control

MOON DAILY
N. Korean leader hails solid-fuel rocket success

US Should Use More Cost-Effective Russian-Made RD-180 Engine

Robert Goddard's Rocket and the Launch of Spaceflight

Engine Test Marks Major Milestone on NASA's Journey to Mars

MOON DAILY
China's 1st space lab Tiangong-1 ends data service

China's aim to explore Mars

China to establish first commercial rocket launch company

China's ambition after space station

MOON DAILY
Unmanned Cygnus cargo ship launches to ISS on resupply run: NASA

Cygnus Set to Deliver Its Largest Load of Station Science, Cargo

Three new members join crew of International Space Station

Grandpa astronaut to break Scott Kelly's space record




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News








The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.