Posted on 10/04/2004 10:31:59 AM PDT by SunkenCiv
This figure for the orbital period (and Earth's rotational period) is wrong, and obviously based on some kind of retrocalculation under the assumption of an impact origin. Gedney's explanation is clearer, older, and based on the fossil evidence. Although the nautiloid fossils have been used to prop up the impact origin for the Moon, the fact that more than 50 per cent of the Earth-Moon distance has accumulated in about ten per cent of the purported age of the Moon shows it isn't so.The MoonThe moon is Earth's only natural satellite... The Moon's orbit is expanding over time as it slows down (the Earth is also slowing down as it loses energy). For example, a billion years ago, the Moon was much closer to the Earth (roughly 200,000 kilometers) and took only 20 days to orbit the Earth. Also, one Earth 'day' was about 18 hours long (instead of our 24 hour day). The tides on Earth were also much stronger since the moon was closer to the Earth.
Enchanted Learning
Please FREEPMAIL me if you want on, off, or alter the "Gods, Graves, Glyphs" PING list --
Archaeology/Anthropology/Ancient Cultures/Artifacts/Antiquities, etc.
The GGG Digest -- Gods, Graves, Glyphs (alpha order)
A really, really old topic ping...
Study Details Crash That Created Moon
News/Current Events News Keywords: X FILES SECTION
Source: discovery online
Published: aug-16-2001 Author: discovery online
Posted on 08/16/2001 18:00:03 PDT by green team 1999
http://www.freerepublic.com/forum/a3b7c6c932c43.htm
New Details on Planetary Crash That Created Moon
Culture/Society News
Source: Yahoo
Published: 08/15/01 Author: Deborah Zabarenko
Posted on 08/15/2001 20:43:08 PDT by Moonman62
http://www.FreeRepublic.com/forum/a3b7b414c3f78.htm#31
http://www.FreeRepublic.com/forum/a3b7b414c3f78.htm#34
http://www.FreeRepublic.com/forum/a3b7b414c3f78.htm#41
In the shadow of the Moon
New Scientist ^ | 30 January 1999 | editors
Posted on 08/31/2004 8:42:25 AM PDT by SunkenCiv
http://www.freerepublic.com/focus/f-chat/1203912/posts
...the Moon clearly could not have been the satellite of the Earth then, for a total period of about 2,000 million years... Spurr points out that the face of the Moon shows two systems of great surface fractures, or faults, lying about 30 degrees from the two poles and trending from west-south-west to east-north-east. This is explained by him as a result of the halting of the Moon's rotation... Curiously, the face of the Earth, too, shows a similar structure, with the same general trend -- the Highland Boundary Fault... The poles of the Earth would also seem to have shifted place on at least three occasions, in the Cambrian, Permian, and (lastly) Quaternary Periods, brining ice and cold to previously warm lands... some mighty force made the crust of the Earth slip (the rotational stability of the axis of a mass as large as the Earth is enormous) and the position of the poles wobbled... there exists on the Moon a triple grid of surface fractures... perpendicular to each other within each grid, the grids being of different ages... Cambrian, Perm-Carboniferous, and Tertiary.Fascinating idea, based though it is on outmoded ideas about impact (i.e., Firsoff's view that there was no role for impact). He's basically given us a snapshot of the problems inherent with a fission origin (either by overspin or by impact), not least of which is that the fission origin also requires in orbit formation of the lunar sphere and capture by the Earth, while showing that capture is possible.
Unlike any other satellite, the Moon completes her revolution round the Earth outside the sphere of the latter's gravitational predominance. Solar and terrestrial gravity draw level with each other at the distance of 161,800 miles from the center of the Earth, whereas the Moon never comes any nearer it than 221,463 miles.But I dunno if this is true. Objects in prograde orbit around the parent body will accelerate and thus raise altitude, while those in retrograde do the opposite. So, a body in orbit could wind up in escape, particularly if a third body were givin' it a come-hither.
George W. Bush will be reelected by a margin of at least ten per cent
Firsoff has been superseded by evidence.
Formation from impact fits the evidence.
SunkinCiv, I would listen to this expert.
Thanks FF. From the first couple of posts:
"Although the nautiloid fossils have been used to prop up the impact origin for the Moon, the fact that more than 50 per cent of the Earth-Moon distance has accumulated in about ten per cent of the purported age of the Moon shows it isn't so."
1) How was it formed, 2) what is it made of, and 3) how far away is it are some of the questions that we can begin to answer.
1) How was the Moon formed?
There were at least five major ideas that were proposed as to the formation of the Moon.
Fission – The Moon split off from the Earth.
Capture – The Moon was captured by the gravity of the Earth.
Condensation – The Moon coalesced out of the same “stuff” the Earth did.
Colliding Planetesimals – Formed from colliding Planetesimals during the early formation of the solar system.
Collision – A body collided with the Earth causing a piece of the Earth’s crust to form the Moon from a resultant ring produced by that collision
The evidence points to the collision theory. First, the Moon does not have an iron core. This pretty much rules out that it coalesced from the same cloud of debris that the Earth did. Second, throughout the solar system, the oxygen isotopes have been found to be different. If the Moon were captured, it too would not match the Earth’s oxygen isotope ratio (which it does). Fourth, by looking at the angular momentum and energy required, the theory that the Moon spun off the Earth after the Earth formed does not hold up.
This leaves us with the Collision theory as the best model we have for the formation of the Moon. The resultant collision caused a ring of debris from the Earths crust to form outside the Roche limit. If it had not, tidal forces would have not allowed for the Moon we see today.
A more in depth discussion of tidal locking since the Moon is tidal locked to the Earth. The reason the Moon keeps one face to the Earth (Its rotation on its axis matches the period of its orbit) is it is tidally locked to the Earth. Here is a more in depth explanation. The total angular momentum of the earth moon system, which is spin angular momentum plus the orbital angular momentum, is constant. (The Sun plays apart also) Friction of the oceans caused by the tides is causing the Earth to slow down a tiny bit each year. This is approximately two milliseconds per century causing the moon to recede by about 3.7 centimeters per year. As the Earth slows down, the Moon must recede to keep the total angular momentum a constant. In other words as the spin angular momentum of the earth decreases, the lunar orbital angular momentum must increase. Here is an interesting side note. The velocity of the moon will slow down as the orbit increases.
Another example of tidal locking is the orbit period and rotation of the planet Mercury. What is interesting about this one is that instead of a 1:1 synchronization where Mercury would keep one face to the Sun at all times, it is actually in a 2/3:1 synchronization. This is due to the High eccentricity of its orbit.
There also can be more than one body “locked” to each other. Lets take a look at the moon Io. Io is very nearly the same size as the Earth’s moon. It is approximately 1.04 times the size of the moon. There is a resonance between Io, Ganymede, and Europa. Io completes four revolutions for every one of Ganymede and two of Europa. This is due to a Laplace Resonance phenomenon. A Laplace Resonance is when more than two bodies are forced into a minimum energy configuration.
2) What is the Moon made of?
From here:
http://lunar.arc.nasa.gov/science/geochem.htm
“Primary elements: The lunar crust is composed of a variety of primary elements, including uranium, thorium, potassium, oxygen, silicon, magnesium, iron, titanium, calcium, aluminum and hydrogen. When bombarded by cosmic rays, each element bounces back into space its own radiation, in the form of gamma rays. Some elements, such as uranium, thorium and potassium, are radioactive and emit gamma rays on their own. However, regardless of what causes them, gamma rays for each element are all different from one another -- each produces a unique spectral "signature," detectable by an instrument called a spectrometer. A complete global mapping of the Moon for the abundance of these elements has never been performed.
Hydrogen and helium: Because its surface is not protected by an atmosphere, the Moon is constantly exposed to the solar wind, which carries both hydrogen and helium -- each potentially very valuable resources. One natural variant of helium, [3]helium, is the ideal material to fuel fusion reactions. When scientists develop a more thorough understanding of fusion, and can practically implement such reactions, the Moon will be a priceless resource, since it is by far the best source of [3]helium anywhere in the Solar System.”
This pretty much answers the question; are there valuable materials up there?
3) What is the distance to the Moon?
The mean distance to the Moon is approximately 238,800 miles. From past experience, we can design spacecraft to get there in about three days. This is far shorter than the months the early voyages took to the new world.
Final thoughts on the Moon.
So here we have this tremendous resource at our fingertips. Unfortunately (not unlike the early explorers), the initial cost is staggering. However, in the long run it would end up being an invaluable resource for both material and scientific study. One of the big advantages is that the Moon keeps one side facing the Earth. This minimizes communication problems between the two bodies. Also since the backside of the Moon is shielded from the Earth, it would be an ideal spot to place a radio telescope array.
First, the Moon does not have an iron core. This pretty much rules out that it coalesced from the same cloud of debris that the Earth did.:') That is evidence in support of capture. The apparent lack of an iron core -- the Earth's is 90 per cent iron, with about 10 per cent other stuff -- also suggests it wasn't born of the Earth, but obviously, either through an impact or an overspin one could suppose it would be made of core material. It would indicate a formation further out in the solar system.
If the Moon were captured, it too would not match the Earth’s oxygen isotope ratio...There's no reason to expect it wouldn't -- the supposed impactor would contribute some (http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1669.pdf assumes 50 per cent) of the lunar material, which means the supposed impactor must have had oxygen isotopes essentially identical to those of the Earth. It's simpler to say, there were two, not three. In addition, the lunar surface has been under bombardment continually for billions of years, and the oxygen isotope ratios of the incoming material must have had no contaminating effect at all.
George W. Bush will be reelected by a margin of at least ten per cent
Genesis' Broken Capsule Holds Good Science - NASAThe charged particles of solar wind, ejected from the upper atmosphere of the sun, are expected to help scientists learn how the sun and planets formed some 4.5 billion years ago, and could give clues on the evolution of the solar system.
Reuters via Yahoo ^ | Sept 13 2004 | Deborah Zabarenko
Posted on 09/13/2004 9:24:30 PM PDT by RightWingAtheist
another GGG topic (from the Catastrophism subsection):
Small Comets and Our Origins
University of Iowa ^ | circa 1999 | Louis A. Frank
Posted on 10/19/2004 11:13:25 PM PDT by SunkenCiv
http://www.freerepublic.com/focus/bloggers/1250694/posts
other lunar topics I've started:
A Celestial Collision
Alaska Science Forum ^ | February 10, 1983 | Larry Gedney
Posted on 09/15/2004 9:04:28 AM PDT by SunkenCiv
http://www.freerepublic.com/focus/f-chat/1216757/posts
It Came from Outer Space?
American Scientist ^ | November-December 2004 | David Schneider
Posted on 11/25/2004 5:13:07 PM PST by SunkenCiv
http://www.freerepublic.com/focus/chat/1288537/posts
bttt, plus some links to other FR topics:
Earth's magnetic poles on verge of flipping
World Net Daily | December 12, 2003
Posted on 12/13/2003 8:38:30 PM PST by gitmo
http://www.freerepublic.com/focus/f-news/1039977/posts
In the shadow of the Moon
New Scientist | 30 January 1999 | editors
Posted on 08/31/2004 8:42:25 AM PDT by SunkenCiv
http://www.freerepublic.com/focus/f-chat/1203912/posts
Jupiter's Spots Disappear Amid Major Climate Change
Space.com | 21 April 2004 | Robert Roy Britt
Posted on 04/21/2004 2:04:19 PM PDT by Yo-Y
http://www.freerepublic.com/focus/f-news/1121982/posts
Massive Object Calls Planet Discoveries into Question
Space dot com (via Yahoo) | Thu, Jan 20, 2005 | Robert Roy Britt
Posted on 01/21/2005 9:19:56 AM PST by SunkenCiv
http://www.freerepublic.com/focus/f-chat/1325494/posts
Scientific maverick's theory on Earth's core up for a test
SF Chronicle | Monday, November 29, 2004 | Keay Davidson
Posted on 12/05/2004 11:17:28 AM PST by SunkenCiv
http://www.freerepublic.com/focus/f-chat/1294934/posts
Scientists Find That Saturn's Rotation Period Is A Puzzle
University of Iowa | June 28, 2004 | Gary Galluzzo and Don Gurnett
Posted on 01/13/2005 6:00:04 PM PST by SunkenCiv
http://www.freerepublic.com/focus/f-chat/1320410/posts
Sun's rays to roast Earth as poles flip
The Observer (U.K.) | 11/10/2002 | Robin McKie
Posted on 11/09/2002 5:59:37 PM PST by Pokey78
http://www.freerepublic.com/focus/f-news/786012/posts
New evidence for the Moon's soft middle
New Scientist | 14 February 2002 | Will Knight
Posted on 12/27/2004 2:29:35 PM PST by SunkenCiv
http://www.freerepublic.com/focus/f-chat/1309193/posts
A Celestial Collision
Alaska Science Forum | February 10, 1983 | Larry Gedney
Posted on 09/15/2004 9:04:28 AM PDT by SunkenCiv
http://www.freerepublic.com/focus/f-chat/1216757/posts
Giordano Bruno, the June 1975 Meteoroid Storm, Encke, and Other Taurid Complex Objects
Icarus (Volume 104, Issue 2 , pp 280-290) | August 1993 | Jack B. Hartung
Posted on 12/27/2004 2:37:46 PM PST by SunkenCiv
http://www.freerepublic.com/focus/chat/1309198/posts
It Came from Outer Space?
American Scientist | November-December 2004 | David Schneider
Posted on 11/25/2004 5:13:07 PM PST by SunkenCiv
http://www.freerepublic.com/focus/chat/1288537/posts
Early Earth Not So Hellish, New Study SuggestsWatson claims there were oceans and continental crust similar to what we have today. "Our data support recent theories that Earth began a pattern of crust formation, erosion, and sediment recycling as early in its evolution as 4.35 billion years ago," he said. Even with the existence of water and crust, the Earth was not the friendly place we now know. The planet would still have been quite hot, and the atmosphere would have consisted only of carbon dioxide, water, and volcanic gases. But life may still have been able to exist in these types of conditions. After all, scientists today find bacteria and other microbes living in similarly hostile conditions.
by Bjorn Carey
5 May 2005New View of Early Earth: A Habitable PlaceA new study concludes Earth had continents and oceans 4.3 billion years ago, which is just a geological eyeblink after the planet is thought to have formed, in the wake of the Sun's birth 4.6 billion years ago. A separate study reported in May came to a similar conclusion, also suggesting that notions of a fiery, hellish planet back then have been overblown... A world with water and land and somewhat moderate temperatures and volcanic conditions would have been habitable. That does not mean there was life, but the conditions were in place... The conclusion is based on an analysis of hafnium, a rare element in ancient minerals from the Jack Hills in Western Australia. The rocks are thought to be among the oldest on Earth, dated to 4.4 billion years ago... The research, led by Mark Harrison of the Australian National University, builds on work Mojzsis and colleagues reported in 2001 that showed evidence for water on Earth's surface roughly 4.3 billion years ago... Scientists do not know exactly when life began or how it got started. If it did begin 4.3 billion years ago, it may have been wiped out by space rock impacts, only to start up again, other theorists say. At any rate, Earth was a treacherous place for the first billion years or so, until it had helped scoop up many of the asteroids and comets that filled the early solar system.
by Robert Roy Britt
18 November 2005
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