Astronomers Say Moons Like Ours Are Uncommon

[C1ay]

The next time you take a moonlit stroll, or admire a full, bright-white moon looming in the night sky, you might count yourself lucky. New observations from NASA's Spitzer Space Telescope suggest that moons like Earth's - that formed out of tremendous collisions - are uncommon in the universe, arising at most in only 5 to 10 percent of planetary systems.

 

lefthttp://hypography.com/gallery/files/9/9/8/earth-moon_thumb.jpg[/img]"When a moon forms from a violent collision, dust should be blasted everywhere," said Nadya Gorlova of the University of Florida, Gainesville, lead author of a new study appearing Nov. 20 in the Astrophysical Journal. "If there were lots of moons forming, we would have seen dust around lots of stars - but we didn't."

 

It's hard to imagine Earth without a moon. Our familiar white orb has long been the subject of art, myth and poetry. Wolves howl at it, and humans have left footprints in its soil. Life itself might have evolved from the ocean to land thanks to tides induced by the moon's gravity.

 

Scientists believe the moon arose about 30 to 50 million years after our sun was born, and after our rocky planets had begun to take shape. A body as big as Mars is thought to have smacked into our infant Earth, breaking off a piece of its mantle. Some of the resulting debris fell into orbit around Earth, eventually coalescing into the moon we see today. The other moons in our solar system either formed simultaneously with their planet or were captured by their planet's gravity.

 

Gorlova and her colleagues looked for the dusty signs of similar smash-ups around 400 stars that are all about 30 million years old - roughly the age of our sun when Earth's moon formed. They found that only 1 out of the 400 stars is immersed in the telltale dust. Taking into consideration the amount of time the dust should stick around, and the age range at which moon-forming collisions can occur, the scientists then calculated the probability of a solar system making a moon like Earth's to be at most 5 to 10 percent.

 

"We don't know that the collision we witnessed around the one star is definitely going to produce a moon, so moon-forming events could be much less frequent than our calculation suggests," said George Rieke of the University of Arizona, Tucson, a co-author of the study.

 

In addition, the observations tell astronomers that the planet-building process itself winds down by 30 million years after a star is born. Like our moon, rocky planets are built up through messy collisions that spray dust all around. Current thinking holds that this process lasts from about 10 to 50 million years after a star forms. The fact that Gorlova and her team found only 1 star out of 400 with collision-generated dust indicates that the 30-million-year-old stars in the study have, for the most part, finished making their planets.

 

"Astronomers have observed young stars with dust swirling around them for more than 20 years now," said Gorlova. "But those stars are usually so young that their dust could be left over from the planet-formation process. 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."

 

For moon lovers, the news isn't all bad. For one thing, moons can form in different ways. And, even though the majority of rocky planets in the universe might not have moons like Earth's, astronomers believe there are billions of rocky planets out there. Five to 10 percent of billions is still a lot of moons.

 

Other authors of the paper include: Zoltan Balog, James Muzerolle, Kate Y. L. Su and Erick T. Young of the University of Arizona, and Valentin D. Ivanov of the European Southern Observatory, Chile.

 

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology, also in Pasadena. Caltech manages JPL for NASA.

 

For more information about Spitzer, visit NASA - SPITZER and Spitzer Space Telescope.

 

Source: Spitzer

[HydrogenBond]

Another way to interpret this data is the collision theory is wrong. Or the formation of the moon by other means is 99.75% more likely.

[InfiniteNow]

Another way to interpret this data is the collision theory is wrong. Or the formation of the moon by other means is 99.75% more likely.

 

No. That is not a valid interpetation of the data shared above. Also, surely if you're offering such a precise number you have some sources to support your claim. Share that source with the rest of us, so we know you're not just pulling numbers and conclusions from your anus.

 

 

 

Theories of Formation for the Moon

Five serious theories have been proposed for the formation of the Moon (not counting the one involving green cheese):

 

1. The Fission Theory: The Moon was once part of the Earth and somehow separated from the Earth early in the history of the Solar System. The present Pacific Ocean basin is the most popular site for the part of the Earth from which the Moon came.
    
    
   
2. The Capture Theory: The Moon was formed somewhere else, and was later captured by the gravitational field of the Earth.
    
    
   
3. The Condensation Theory: The Moon and the Earth condensed together from the original nebula that formed the Solar System.
    
    
   
4. The Colliding Planetesimals Theory: The interaction of earth-orbiting and Sun-orbiting planetesimals (very large chunks of rocks like asteroids) early in the history of the Solar System led to their breakup. The Moon condensed from this debris.
    
    
   
5. The Ejected Ring Theory: A planetesimal the size of Mars struck the earth, ejecting large volumes of matter. A disk of orbiting material was formed, and this matter eventually condensed to form the Moon in orbit around the Earth.
   

 

 

Constraints from Recent Data

 

A detailed comparison of the properties of Lunar and Earth rock samples has placed very strong constraints on the possible validity of these hypotheses. For example, if the Moon came from material that once made up the Earth, then Lunar and Terrestrial rocks should be much more similar in composition than if the Moon was formed somewhere else and only later was captured by the Earth.

 

These analyses indicate that the abundances of elements in Lunar and Terrestrial material are sufficiently different to make it unlikely that the Moon formed directly from the Earth. Generally, work over the last 10 years has essentially ruled out the first two explanations and made the third one rather unlikely. At present the fifth hypothesis, that the Moon was formed from a ring of matter ejected by collision of a large object with the Earth, is the favored hypothesis; however, the question is not completely settled and many details remain to the accounted for.

 

 

 

 

 

Where did the Moon come from?

For nearly a decade, the giant impact theory was not believed by most scientists. However, in 1984, a conference devoted to lunar origin prompted a critical comparison of the existing theories. The giant impact theory emerged from this conference with nearly consensus support by scientists, enhanced by new models of planet formation that suggested large impacts were actually quite common events in the late stages of terrestrial planet formation.

 

The basic idea is this: about 4.45 billion years ago, a young planet Earth -- a mere 50 million years old at the time and not the solid object we know today-- experienced the largest impact event of its history. Another planetary body with roughly the mass of Mars had formed nearby with an orbit that placed it on a collision course with Earth. When young Earth and this rogue body collided, the energy involved was 100 million times larger than the much later event believed to have wiped out the dinosaurs. The early giant collision destroyed the rogue body, likely vaporized the upper layers of Earth's mantle, and ejected large amounts of debris into Earth orbit. Our Moon formed from this debris.

 

 

[HydrogenBond]

The fact that Gorlova and her team found only 1 star out of 400 with collision-generated dust indicates that the 30-million-year-old stars in the study have, for the most part, finished making their planets.

 

The number was based on the article which has other, 400 to 1. The dust not being there, assumes there were collisions. Maybe there is no dust because collisions were not part of the process. The researchers are trying to remain in the loop, out of fear, that a trap door will open, due to band wagon bias. If the band wagon used green cheese, they would accommodate that. The obvious is not allowable only the long shot is acceptable.

 

I tend to like the condensation theory since it simply gets any material in a spiraling motion, with smaller and smaller eddies forming. Gravity only has to open the drain in the tub of space-time, the space-time vortex creates smaller eddies. The difference in the material between earth and moon is inconclusive since we only have a tiny sample. I can do that on earth gathering a sample of silica rich Florida sand and iron rich Georgia clay and assume two different planets. Or two different asteroids, etc.

 

We need to go further back in time to figure out why we are defending the collision assumption and then forcing the data to make this look correct. The current physics does not allow the sun to make heavy elements from H. This same theory can't make controlled fusion work either. To protect that, anyway, we need to make the heavy elements elsewhere. Based on the technique of a particle accelerator, we use a collapsing star that goes nova to make material. This stays mainstream without hurting feelings.

 

A simple old fashion solar system condensation makes more sense. It simply condenses out of what ever material is present not requiring some very specific pre-event. Here is one possible model. The sun formed from hydrogen during its initial phase. As the small atoms build, the heavier can't sink due to the energy turbulence. What is sinking is not sinking at all, but it is diffusing to the fusion core due to the energy potential for fusion. As the atoms grow and lower their potential for fusion they collect above the core. The reason they do this is the inner most orbital electrons begin to stick longer and longer causing restricted space around the nuclei making them less dense. Their new density is not dense nuclear but is a fluffier type of pseudo-atomic.

 

What begins to happen is a shell of this fluffier pseudo-atom material is thickening around the fusion core, interfering with the diffusion into and out of the fusion core. Solar flares and sunspots reflect the dynamics of the shell as it is being ruptured and also trying to reseal. The pressure pulses and core heat allow even higher atoms to form, thickening the shell. Eventually the shell disrupted diffusion causing the core to cool. The shell began to collapse, causing cracks to appear allowing a fuel surge. The result was the sun purged the shell to form the material for the solar system. The sun got a second life and the planets slowly formed. The rocky inner planets and the gaseous outer planets reflect the material ejection profile of round 1.

 

The reason solar systems are not common is that they require an ejection profile that is not too extreme or analogous to a supernova. They need to be sort of sub-nova but strong enough to crack and scatter the shell so the fusion core is not totally disrupted and can restore maxima fusion. Our sun is undergoing its second life, with a third well into the future.

[Tormod]

The researchers are trying to remain in the loop, out of fear, that a trap door will open, due to band wagon bias.

 

Please refrain from posting conspiracy theories, especially when they are pulled out of the blue and have no relation to the topic.

 

The posted news item is a tiny piece of the results from a study of 400 young stars of approximately the same age (30 million). Their theories are simply educated guesswork. The sample is too small to make anything but assumptions.

[HydrogenBond]

I was pressed for time because I needed to head out. I didn't have time to look at what I wrote. I was not implying a conspiracy theory. I was only interpreting the article in a way that suggested the 400 to 1 observation of little impact dust, could also be interpreted to mean that impact genesis is not very likely. The author of the article, was favoring an impact theory for the moon. He even went so far as suggesting what we didn't see in the data, nevertheless happened for the moon. I sensed a built in bias; "moons like are our are special and different in spite of the data suggesting otherwise" Nobody wants to be the first to criticize the latest fad in moon genesis. I could hear eggshells crunching, so I thought I would point this out.