Posted on 11/20/2007 7:40:12 PM PST by NormsRevenge
The moon formed after a nasty planetary collision with young Earth, yet it looks odd next to its watery orbital neighbor. Turns out it really is odd: Only about one in every 10 to 20 solar systems may harbor a similar moon.
New observations made by NASA's Spitzer Space Telescope of stellar dust clouds suggest that moons like Earth's are—at most—in only 5 to 10 percent of planetary systems.
"When a moon forms from a violent collision, dust should be blasted everywhere," said Nadya Gorlova, an astronomer at the University of Florida in Gainesville who analyzed the telescope data in a new study. "If there were lots of moons forming, we would have seen dust around lots of stars. But we didn't."
Gorlova and her team detail their findings in today's issue of the Astrophysical Journal.
Violent birth
Shortly after the sun formed about 4.5 billion years ago, scientists think a vagrant planet as big as Mars smacked into infant Earth and ripped off a chunk of our home's smoldering mantle. The rocky, dusty leftovers fell into orbit around our wounded planet, eventually coalescing into the moon we see today.
The scenario is unique among other moons in the solar system, which formed side-by-side with their planet or were captured by its gravity. Gorlova and her colleagues looked for the dusty signs of similar smash-ups around 400 stars, all about 30 million years old—roughly the age of our sun when Earth's moon formed.
Only one of all the stars they studied, however, displayed the telltale dust. Considering the frequency of planetary solar systems, the amount of time the dust should stick around and the window for moon-forming collisions to occur, the scientists were able to peg the frequency of extrasolar bodies that formed like our moon.
The estimate, however, is possibly a generous one.
"We don't know that the collision we witnessed around the one star is definitely going to produce a moon," said study co-author George Rieke, an astronomer at the University of Arizona in Tucson, "so moon-forming events could be much less frequent than our calculation suggests."
Odd moon out?
Planetary scientists like Gorlova and Rieke think infant solar systems can form moons between 10 and 50 million years after a star forms. That only a single star with collision-generated dust could be found in their latest research, the astronomers said, indicates that the 30 million-year-old stars in the study have finished making their planets.
"Astronomers have observed young stars with dust swirling around them for more than 20 years now," said Gorlova, noting that the dust could be collision-derived or primitive planet-forming material. "The star we have found is older, at the same age our sun was when it had finished making planets and the Earth-moon system had just formed in a collision."
While most the our type of moon may be rare, astronomers think there are billions of rocky planets out there with plenty of moons orbiting around them. The upshot for lunar lovers? There could be millions—or billions—of Earth-like moons drifting through the cosmos.
The Moon is truly unique. It's close enough to Earth to cover the Sun's disk so that during total eclipses we can measure the Suns's gravitational bending of distant starlight consistent and confirming of General Relativity.
The Moon stabilizes the Earth's tilt which give us the seasons, and it may act too, gravitationally, to modify plate tectonics within the earth, without which, human life could not have been possible.
Combined with all the other "coincidences" which give us the life we know, is more evidence than not, for the existence of God.
Extrasolar Planets: Testing Models of Planet Formation -- "Roche Limit & Migration... Circularization of highly eccentric orbits with small pericenter distances: Predicts edge at twice the Roche limit, Planet-planet scattering, tidal-capture of free-floating planets... Formation of Uranus & Neptune, Problem: Standard timescale to accrete Neptune in situ at ~30 AU exceeds 4 Gyr... Our own solar system may have once contained giant planets on eccentric orbits."
Chinese Scientist Gives New Hypothesis on Origin of the MoonA planet collision may have helped form the Moon. This is the new hypothesis on the origin of the Moon by Huang Jinzhong, a geographer from the Seismology Bureau of Quanzhou City. Huang said two planets, between the orbits of Mars and Jupiter, collided and split some 4.6 billion years ago, and one of the fragments formed rudiments of the Moon. Huang supported his hypothesis with evidence of the Moon's internal structure and chemical components, the age of rocks on the Moon, and other geological data. A planet collision may have helped form the Moon. This is the new hypothesis on the origin of the Moon by Huang Jinzhong, a geographer from the Seismology Bureau of Quanzhou City, Fujian Province, according to latest issue of Beijing Review.
People's Daily
Thursday, November 29, 2001Rudiments of the Moon Comes From FragmentsIn a paper submitted to the annual meeting of the China Association for Science and Technology (CAST), Huang said two planets, between the orbits of Mars and Jupiter, collided and split some 4.6 billion years ago, and one of the fragments formed rudiments of the Moon.
This rudiment Moon was a melting celestial body, circling the Sun, according to Huang. Influenced by Jupiter's gravitation, its orbit began to change. The rudiment Moon collided with the South Pole region of the Earth some 4.46 billion years ago, and rebounded from it. The rebound force and Earth's centrifugal force then caused the Moon to circle around the Earth, he said.Evidence from Structure & Chemical ComponentsHuang supported his hypothesis with evidence of the Moon's internal structure and chemical components, the age of rocks on the Moon, and other geological data. Huang's hypothesis on the origin of the Moon comes from his theory of the genesis of the Solar System. Japanese geologist C. Hayaci said Huang's theory is an innovative school of thought in the field.
There have been four hypotheses on the origin of the Moon so far: First, the Moon was a fragment separated from the Earth; second, the Moon was an independent planet captured by the Earth's gravitational pull; third, both the Moon and the Earth were formed by the same cluster of celestial material; and fourth, the Moon was formed by substances sent out after a huge planetestimal collision with the Earth. Yet all of these theories are considered flawed in certain aspects.
(the main champion of impact)
Origin Of The Moon
H. Jay Melosh
http://www.lpl.arizona.edu/outreach/origin/
“The last big impact, which probably formed the Earth’s Moon, was the most energetic.” — Michael J. Drake, “Accretion and primary differentiation of the Earth: A personal journey”, February 7, 2000.
http://www.lpl.arizona.edu/faculty/drake_papers/Drake2000.pdf
An artist's rendering of what the environment around Pleiades star HD 23514 might look like as two planets collide. Small, rocky planets that could resemble the Earth or Mars may be forming around a star in the Pleiades star cluster, astronomers reported on Wednesday. (Gemini Observatory/Lynette R. Cook/Reuters)
...but only slightly. ;’)
The moon was one of the larger bodies orbiting Tiamat and was captured by Marduk after the collision, but only briefly, as it joined with Earth to share the new orbit of the remains of Tiamat. The center of balance (I forget what it's called) is a mile or two beneath the Earth's surface.
There is, alas, no Marduk and there was no Tiamat. :’)
Zecharia Sitchin's Errors: An OverviewThe study shows - from the texts themselves, not my opinion - that "Nibiru" is not a planet beyond Pluto and that the Anunnaki gods are never associated with it. These ideas are fabrications... This study details the impossibility of Sitchin's translations of "nephilim" as "those who came down" or "people of the fiery rockets" in light of Hebrew vocabulary and grammar. I know it sounds mind- numbing, but again I have tried to illustrate the concepts and problems. It also contains a scan of a page from one of Sitchin's books where he could not tell the difference between Aramaic and Hebrew - an amazing mistake if he's an expert... Mr. Sitchin contends that the word "Nephilim" means "those who came down from above" or "those who descended to earth" or "people of the fiery rockets" (see The Twelfth Planet, pp. vii, 128ff.). These translations, of course, serve his purpose - to see the Nephilim as ancient astronauts. As such it is hard to over-estimate the importance of Sitchin's work here - if he's wrong about the meaning of "nephilim," much of his overall thesis falls... Sitchin assumes "Nephilim" comes from the Hebrew word "naphal" (as opposed to ARAMAIC - see below) which usually means "to fall." He then forces the meaning "to come down" onto the word, creating his "to come down from above" translation. "Nephilim" - in the form we find it in the Hebrew Bible - COULD come from Hebrew "naphal," but it could ONLY mean be translated one way in light of the spelling - "those who are fallen" (i.e., either "fallen in battle" - which is out of the question given the context of Genesis 6 - or "spiritually fallen" / evil - which fits the context IF the sons of God are evil)... In short, if you care about the grammar of Hebrew, Sitchin's word meanings CAN'T be correct. The above file also discusses Sitchin's confusion of the sons of God and the nephilim - and evidence from his own book, Stairway to Heaven, that he cannot distinguish between Hebrew and Aramaic! My suspicion behind this apparent blunder is that Sitchin wants to distance the Annunaki from the evil Watchers of ancient Jewish literature (Hebrew Bible, Enoch, and some Dead Sea Scrolls).
by Michael S. Heiser
I would offer a link in return, but the book I would recommend, "Godstone" by Tim Rivers and Joe Schultz isn't online nor has it been published. I have one of the manuscripts which has been passed around privately.
Hey, if the clock stops at 7... ;’)
I believe it was Asimov who first brought to me the statement that our large Moon is very unusual, and possibly life-giving to Earth. If this turns out to be true, I’ll gain even more respect for him, even if it wasn’t an original thought of his.
Earth's Moon is Rare Oddball
Earth’s Moon is ‘cosmic rarity’
BBC News | 21 November 2007 | Paul Rincon
Posted on 11/21/2007 1:12:51 PM PST by Aristotelian
http://www.freerepublic.com/focus/f-chat/1929042/posts
Could it have been another planet still forming between Mars and Jupiter (in the asteroid belt), that perhaps got knocked out of orbit by other chunks still there before it was completed, or flung out by the push/pull of Jupiter's gravity on the one side, and the sun and inner planets on the other?
-PJ
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