Ancient lunar polar ice reveals tilting of Moon’s axis

astronomynow.com ^ | 03/23/2016 | NASA

[BenLurkin]

New NASA-funded research provides evidence that the spin axis of the 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 today’s journal 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.

[BenLurkin]

A cross-section through the Moon, highlighting the antipodal nature of lunar polar volatiles (in purple), and how they trace an ancient spin pole. The reorientation from that ancient spin pole (red arrow) to the present-day spin pole (blue arrow) was driven by the formation and evolution of the Procellarum — a region on the nearside of the Moon associated with a high abundance of radiogenic heat producing elements (green), high heat flow, and ancient volcanic activity. Illustration credits: James Tuttle Keane, University of Arizona.

[Samwell Tarly]

Bit of a wobble still from the impact with Theia?

[jonrick46]

Maybe it is the accumulation of stuff from space, causing a change in mass.

[Doogle]

Bush’s fault

[knarf]

Perhaps the man in the moon is considering gender re-orientation

[SunkenCiv]

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Thanks BenLurkin. Lunar Origin keyword, sorted:

• Ancient Earth Remnant Is Inside Earth, Study Says [2014]
• A collision 4.5 billion years ago nearly destroyed our planet but instead helped start path to life [2014]
• Moon created in violent collision with Earth, clues in Apollo rocks suggest. [2014]
• Scientists May Be Wrong About The Amount of Water In The Moon [2014]
• Crystal is 'oldest scrap of Earth crust' [2014]
• Water Hidden in the Moon May Have Proto-Earth Origin [2013]
• How the American West was made --- a new view of plate tectonics [2013]
• Who Needs a Moon? [2011]
• Moon's interior water casts doubt on formation theory [2011]
• Moon has liquid core just like Earth...reveal sensors left on surface by astronauts 40 YEARS ago [2011]
• Astronauts, Artists Agree: Moon Stinks of Gunpowder [2010]
• Where on Earth has our water come from? [2010]
• Water on the Moon: a Billion Gallons [2010]
• Moon Not Only Has Water, but Lots of It [2010]
• Gondwana Supercontinent Underwent Massive Shift During Cambrian Explosion [2010]
• The Earth and moon formed later than previously thought [2010]
• The Moon may have formed in a nuclear explosion [2010]
• Why is the Earth moving away from the sun? [2009]
• STEREO Hunts for Remains of an Ancient Planet near Earth... [2009]
• The Search for the Solar System's Lost Planet [2009]
• STEREO Hunts for Remains of an Ancient Planet near Earth [2009]
• Quakes triggered by tides of solid Earth [2009]
• The Curious Case of Missing Asteroids [2009]
• Far side of the moon 'could have been visible from earth' [2009]
• Were Mercury and Mars separated at birth? [2009]
• Did Earth's Twin Cores Spark Plate Tectonics? [2009]
• Moon Has Iron Core, Lunar-Rock Study Says [2008]
• Moon Is Younger And More Earth-Like Than Thought [2007]
• Earth's Moon is 'cosmic rarity' [2007]
• Earth's Moon is Rare Oddball [2007]
• Ancient impact may have bowled the Moon over [2007]
• Far-Flung Space Crash May Help Solve Mystery of Moon's Formation [2007]
• Landscapes from the ancient and eroded lunar far side [2006]
• Planets Around Planets? [2006]
• Neptune Might Have Captured Triton [2006]
• An explosion on the Moon [2005]
• Comet or Meteorite Impact Events in 1178AD? [2005]
• New evidence for the Moon's soft middle [2004]
• It Came from Outer Space? [2004]
• When the Days Were Shorter [2004]
• A Celestial Collision [2004]
• In the shadow of the Moon [2004]
• No Moon, no life on Earth, suggests theory [2004]
• Long-Destroyed Fifth Planet May Have Caused Lunar Cataclysm, Researchers Say [2002]

[SunkenCiv]

The Big Splash keyword, also relevant:

http://www.freerepublic.com/tag/bigsplash/index

[Verginius Rufus]

News you can use.

[Verginius Rufus]

News you can use.

[clearcarbon]

Maybe the earth and moon collided with an ice cloud long ago that gave earth some extra water and collected frozen on the moon tilting it’s axis. Eventually the moon ice sublimated back into space and the moon axis orientation corrected itself.

[SunkenCiv]

• 'Cloud' over Mars leaves scientists baffled [2015]
• Cosmic Impacts May Have Seeded Early Earth with Ingredients for Life [2015]
• Rosetta Instrument Reignites Debate on Earth's Oceans [2014]
• Water On Earth Is Older Than The Sun [2014]
• Water Hidden in the Moon May Have Proto-Earth Origin [2013]
• We are all made of comet dust [2013]
• Man Captures Video Of Strange Explosion In The Sky [2013]
• Solar System Ice: Source of Earth's Water [2012]
• Amazingly, the earths water is really a miniscule amount [2012]
• Astronomy Picture of the Day -- All the Water on Planet Earth [2012]
• Comet's water 'like that of Earth's oceans' [2011]
• Telescope shoots video of heavenly halo ("mystery flash" filmed from Mauna Kea, Hawaii) [2011]
• Kansas scientists probe mysterious possible comet strikes on Earth [2009]
• Military Covering Up Fireballs From Space [2009]
• Military Covering Up Fireballs From Space.... [2009]
• Did Comets Contain Key Ingredients For Life On Earth? [2009]
• Unseen dark comets 'could pose deadly threat to earth' [2009]
• Clandestine comets found in main asteroid belt -- Earth oceans origin [2006]
• The Comet and the Future of Science [2006]
• Cosmic Hole-in-One Captured Over Antarctica [2005]
• Comet put on list of potential Earth impactors [2005]
• Satellite Photo: What is this? [2005]
• Small Comets and Our Origins [2004]
• An Argument for the Cometary Origin of the Biosphere [2004]
• Did comets flood Earth's oceans? [2004]
• So, where did the water on Mars come from? [2004]
• Big Splash and The Big Splash keywords