Skip to comments.Ancient impact may have bowled the Moon over
Posted on 10/30/2007 7:39:35 PM PDT by SunkenCiv
An enormous impact basin located near the lunar south pole may have caused the Moon to roll over early in its history, new research suggests... Called the South Pole-Aitken (SPA) basin, it is 2500 kilometres wide and 12 kilometres deep and is thought to have been created about 4 billion years ago. Francis Nimmo of the University of California in Santa Cruz, US, believes the impact probably occurred near the Moon's equator. That is because the equator lies in the plane of most other objects in the solar system and therefore would more likely be in a hurtling space rock's 'line of fire'. But he thinks the giant hole destabilised the Moon, so that within 100,000 to 1 million years of forming, the basin - a region of low mass - had rolled over to the south pole... The SPA is not centred exactly on the Moon's south pole, however, but about 30° away. Nimmo thinks that is because the Moon has shifted its orientation slightly since the basin first rolled to the pole. "Presumably the reason that it didn't go all the way to the pole is because other large basins will have also reoriented the Moon," he says. "Quite likely, the Moon was reoriented several times during the early period of large impacts."
(Excerpt) Read more at space.newscientist.com ...
The South Pole-Aitken basin (circled) is the largest impact crater in the solar system. One edge lies on the Moon's south pole, while its centre lies about 30° away (Image: Clementine Project/LPI)
When the Days Were Shorter
Alaska Science Forum (Article #742) | November 11, 1985 | Larry Gedney
Posted on 10/04/2004 1:31:59 PM EDT by SunkenCiv
Long-Destroyed Fifth Planet May Have
Caused Lunar Cataclysm, Researchers Say
SPACE dot COM | 18 March 2002 ,posted: 03:00 pm ET
By Leonard David, Senior Space Writer
Posted on 03/25/2002 5:42:10 PM EST by vannrox
Moon Chemistry Confirms Violent Origin
SPACE.com | 22 August 2006 | Jeanna Bryner
Posted on 08/23/2006 1:24:06 PM EDT by Boxen
International Declaration Signed Advocating Return to the Moon
Space.com | December 5, 2003 | Leonard David
Posted on 12/05/2003 7:30:29 AM EST by Cincinatus’ Wife
Scientists Eager to Explore Moon’s South Pole
Space News | 06-09-2003 | LEONARD DAVID
Posted on 06/16/2003 12:18:06 PM EDT by boris
Scientists, Dreamers Continue Refining Ideas for Future Lunar Bases
Space.com | 7/18/02 | Leonard David
Posted on 07/18/2002 8:07:19 PM EDT by Brett66
Scientists Press NASA To Reconsider Luna
Published: 30 Mar 01 Author: Leonard David
Posted on 03/30/2001 09:50:09 PST by RightWhale
So after the moon and Pluto, what next? Earth? And the feds will mandate all new globes?
Dr. H. Jay Melosh (mentioned in excerpt)
News seems to be a few billions years old, why would I care? (Operative word may). Love that may thingy.
Actually, this one was an “April” thingy. ;’)
No, but maybe a really, really big fielder’s mitt.
Reorientation of icy satellites by impact basins
F. Nimmo and I. Matsuyama
Geophys. Res. Lett. , 34, L19203, 2007
April 1st thingy, I presume? LOL!
17th. Of course, it may have been submitted on the 15th, right after the world ended for the author when he filed his taxes.
Did the new moon lose its iron heart?The current theory says that the material that now forms our moon was ejected when Earth was struck by another planet-sized body. But Peter Noerdlinger at Saint Mary's University in Halifax, Canada, says this theory has problems. "The collision has to be implausibly gentle. You practically need someone to hold a Mars-sized object just above Earth and drop it, to avoid messing up Earth's orbit."
January 23, 2007
The simpler idea that Earth and the moon were both created from the same gas cloud had been rejected because it could not explain why Earth formed an iron core and the moon did not. Now, Noerdlinger has an answer for that.
He suggests that the proto-moon did have an iron core, but that the satellite was ripped apart in a close encounter with Earth. His calculations show that iron from the core would be pulled towards Earth, while the remains of its rocky outer shell reassembled into our iron-free moon.
This fits with evidence that the Earth acquired a veneer of iron after it formed, Noerdlinger says. He presented the work at the American Astronomical Society meeting in Seattle, Washington, last week.
From issue 2587 of New Scientist magazine, 23 January 2007, page 16
Far side of the moon ‘could have been visible from earth’
Telegraph | 1/21/09 | Kate Devlin
Posted on 01/23/2009 12:23:42 AM PST by LibWhacker
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