Slashdot Mirror
New Evidence That the Moon Was Created In a Massive Collision
derekmead writes "New evidence that the giant impact hypothesis is correct: A paper published today in Nature shares findings of a chemical analysis of Moon rocks that shows fractional differences between the makeup of the Earth and Moon that most likely were caused by the collision between Earth and a Mars-sized planet around 4.5 billion years ago. Although the two are quite similar, it's been previously shown that Moon rocks lack volatile elements, which suggests they may have evaporated during the incredibly intense heat and pressure created during an impact event. But if the hypothesis that light elements actually evaporated from Moon rocks during their formation is correct, you'd expect to find evidence of elements being layered by mass — heavier elements would condense first, and so on. That process is known as isotopic fractionation — a concept central to carbon dating — and the Washington University team's results suggest they found exactly that (abstract). They compared the blend of zinc isotopes in Moon rocks and Earth samples, and found that the Moon rocks held slightly higher proportions of heavier zinc isotopes. If the Moon was indeed once part of Earth — which has been shown by extensive modeling (PDF) — the difference in the balance of zinc profiles would most likely be explained by lighter zinc isotopes evaporating away following a collision."
Yeah, and how the hell does the moon work, anyway? Where did it come from? NOBODY KNOWS! NOBODY KNOWS! We'll never know!
This sig is false.
You know, I bet this observation hasn't occurred to the scientists working on this problem. If they hear it, they'll go "OMG you're right! Why didn't we think of that??"
A mars size rock hits the earth, that would create enough heat to melt the rocks and send them into space as a big liquid ball. Those crazy astronauts that play with their drinks show in microgravity that liquid will prefer to be in a sphere shape. So a chunk of liquid rock the size of the moon over Thousands/Millions of years of slowly cooling down would take the shape of a sphere.
Now the moon isn't a perfect sphere, that is because it is spinning while it was cooling and those other gravitational forces shifting it, and once an awhile getting pounded by some other rocks.
Sorry was that a troll?
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
Yeah. You shouldn't hang out with people from Africa either.
Everything is better with chainsaws.
As I am finding in reading quantum theory, common sense is usually wrong
Who DOESNT think the moon was caused by a collision, outside of a few Creationists?
I want to delete my account but Slashdot doesn't allow it.
Evidently you have never visited some of the mining towns I have. I would rather go to the moon.
With some careful interpretation and text analysis of Velikovsky's
works, we may yet find he predicted this.
I think you mean something more like 6012 years old.
I'm guessing this happened before Flash Gordon's time. Who knew that 40's pulp sci-fi was based on facts?
It's like finding George Washington's dried blood on your baseball bat. It's possible there are other ways the blood got there, but you probably just whacked the guy.
Everything is better with chainsaws.
What did the people who only worked 60 hour weeks in grad school believe?
You can read about the reason for the moon's spherical shape here:
http://en.wikipedia.org/wiki/Hydrostatic_equilibrium#Planetary_geology
It's fairly straightforward, nothing at all like Quantum mechanics.
We hope your rules and wisdom choke you / Now we are one in everlasting peace
I wonder what the size of Earth would be if there was no impact event that created the moon. Anyone?
You must gather your party before venturing forth.
...that Pangea (the conglomeration of land which drifted apart to become our current continents) might have been the Earth's "exit wound", where the Moon's material separated. For me, this is a hunch, with no basis in scientific fact, so I'm not going to declare its truth or defend it, but I would not be surprised if, in 10 or 20 years, some evidence were to surface supporting this idea.
I remember being a kid and thinking that South America and Africa would fit together like a puzzle, and this was long before I'd ever heard of Pangea. Since that time, it's my understanding that irrefutable evidence--basically, the matching of fault lines and mineral components--has been found to support this. Later, I remember having the idea that the Moon may have been spit out of the Earth as the result of a large collision. My hunch was specious as it was based only on the idea that its orbit is perfectly matched with its rotation speed (aka tidally locked), and I understand that it's possible for that to happen in other ways, but this seemed to me the best bet.
That last idea led to the Pangea idea. Maybe I'll read the freakin' article to see if other people feel the same way.
The CB App. What's your 20?
It amazes me that so many allegedly "educated" people have fallen so quickly and so hard for a fraudulent fabrication of such laughable proportions. The very idea that a gigantic ball of rock happens to orbit our planet, showing itself in neat, four-week cycles -- with the same side facing us all the time -- is ludicrous. Furthermore, it is an insult to common sense and a damnable affront to intellectual honesty and integrity. That people actually believe it is evidence that the liberals have wrested the last vestiges of control of our public school system from decent, God-fearing Americans (as if any further evidence was needed! Daddy's Roommate? God Almighty!)
Documentaries such as Enemy of the State have accurately portrayed the elaborate, byzantine network of surveillance satellites that the liberals have sent into space to spy on law-abiding Americans. Equipped with technology developed by Handgun Control, Inc., these satellites have the ability to detect firearms from hundreds of kilometers up. That's right, neighbors .. the next time you're out in the backyard exercising your Second Amendment rights, the liberals will see it! These satellites are sensitive enough to tell the difference between a Colt .45 and a .38 Special! And when they detect you with a firearm, their computers cross-reference the address to figure out your name, and then an enormous database housed at Berkeley is updated with information about you.
Of course, this all works fine during the day, but what about at night? Even the liberals can't control the rotation of the Earth to prevent nightfall from setting in (only Joshua was able to ask for that particular favor!) That's where the "moon" comes in. Powered by nuclear reactors, the "moon" is nothing more than an enormous balloon, emitting trillions of candlepower of gun-revealing light. Piloted by key members of the liberal community, the "moon" is strategically moved across the country, pointing out those who dare to make use of their God-given rights at night!
Yes, I know this probably sounds paranoid and preposterous, but consider this. Despite what the revisionist historians tell you, there is no mention of the "moon" anywhere in literature or historical documents -- anywhere -- before 1950. That is when it was initially launched. When President Josef Kennedy, at the State of the Union address, proclaimed "We choose to go to the moon", he may as well have said "We choose to go to the weather balloon." The subsequent faking of a "moon" landing on national TV was the first step in a long history of the erosion of our constitutional rights by leftists in this country. No longer can we hide from our government when the sun goes down.
General Relativity: Space-time tells matter where to go; Matter tells space-time what shape to be.
Going to the moon again will cost billions. Running a few isotopic scans on rocks, involves a grant of several thousand dollars.
Do you grasp the difference between a thousand dollars and a billion dollars?
Now, the war in Iraq probably cost more than ten trips to the moon, and was a far less productive use of our resources - but that's a very different argument.
Changa hates change.
Take it easy with the detail work, man. He's probably a politician.
"If the Moon was indeed once part of Earth — which has been shown by extensive modeling (PDF) — the difference in the balance of zinc profiles would most likely be explained by lighter zinc isotopes evaporating away following a collision."
As a skeptic of the 'giant impact hypothesis' of the Moon's origin:
... but seriously, all of the above is sarcasm.
Collisions between planetary bodies are too complex to model.
I won't believe anything based on computer models unless they simulate the interaction of every single particle in the solar system.
"Garbage in - garbage out."
They obviously just kept tweaking the model until it gave them the result that they wanted.
I have an article from a non-scientific magazine in the 1960's that says the Moon drifted gently into orbit around the Earth.
I need to see a Mars size planet actually collide with an exact duplicate of the Earth and form an identical moon before I'll believe it.
The evidence that the Moon gently drifted into orbit around the Earth is being suppressed from the scientific journals! Fraud! Malpractice! It is all hoax to get lucrative government grant money!
I've posted this as a way to express my frustration with how modeling/simulations and proxy data are treated as "compelling" evidence when we are talking about astronomical science, but modeling/simulations and proxy data are all of a sudden treated as "dubious" when we're talking about climate science.
If you go to any Slashdot article about latest developments in climate science you'll find a bunch of (usually AC) comments that are almost identical to the ones above from climate change "skeptics".
Warning: This sig is not thread safe. For more information see Slashdot's sig policy.
Going to the moon again will cost billions.
The Russians were offering to send you around the moon for a measly $100 million in 2005, and now all these new commercial space ventures are offering the same thing for the same price.
"His name was James Damore."
A sci-fi author (can't recall who) once wrote in a novel that Earth's crust contains a relatively high percentage of heavier elements because of the Moon. Without Moon's (relatively big, as far as satellites are concerned) gravitational pull, heavier elements would've fallen toward Earth's center leaving only lighter ones to cool down and turn solid on the crust.
Can somebody more knowledgeable on the field comment on the theory? Is there any truth in this? Is this an important factor on making a planet habitable for us? Is this an important factor for forming life (as we know it) on a planet?
Better I think would be "New information discovered adds support to theory of moon created by massive collision"
The headline made it sound like it was already established fact. And even though it's correct use of the word, I think that calling this new discovery "evidence" contributes to this confusion. (though it is the strongest current theory, and will probably eventually be accepted as fact although not likely ever proven)
I work for the Department of Redundancy Department.
Hello,
My understanding of current geological theory is that Pangea is just the most recent of a cyclic occurrence of supercontinents.
There have been multiple time periods in Earth's history when most of the land was in one supercontinent, which then split into continents, only to rejoin again. Wikipedia has the cycle at 300M to 500M years.
Here's the wikipedia article. http://en.wikipedia.org/wiki/Supercontinent_cycle
So, I think your exit would theory contradicts current geological theory.
--PeterM
Grandparent is rated -1, but actually I've wondered about this myself. Is your explanation really accurate or are you just guessing?
Intuitively I would also suppose that a body that was formed from a collision rather than a cloud of gas would assume an irregular shape. I mean, many asteroids and moons of Jupiter are probably product of colissions and do have an irregular shape.
Cubical planets typically have "HPLD" written on them.
Mostly random stuff.
There has been a flurry of new models (or significant variations on the old model) suggested recently. They include a smaller than Mars impactor that hit at a higher velocity and a slower impactor that was approximately the same size as the newly formed Earth. Both were inspired by studies that showed that the evection resonance of the Earth-Moon-Sun system would allow for a greater slow down in the rotation of the Earth getting to the contemporary 24 hr day. (see http://io9.com/5952497/further-evidence-that-the-moons-explosive-birth-was-weirder-than-we-thought et al)
Because the started as rotating balls of dust that gradually compacted into solid objects. This causes them to form into roughly spherical objects.
I suppose you're a troll as well, but to hell with it, I'll bite.
Any celestial body large enough to have a sizable gravity (I am sure there's a threshold formula somewhere, but CBA to check) will take, in time, a spherical shape because of... GRAVITY! (applause in the background)
http://www.pa.msu.edu/sciencet/ask_st/031198.html
...gis sdrawkcab (usually not responding to ACs; don't bother posting as AC)
Sometimes I wonder if they understand what a trillion dollars is when you consider how much debt the country is in.
But why are all the planets and moons so round? Why do we not see some that are odd shapes?
Self-gravity. With sufficient mass and radius, gravitational forces overcome the yield strength of the materials and cause even solid bodies to assume a spherical shape. This occurs at about 300km radius. The surface may still be irregular, but overburden pressure causes rocks at depth to undergo plastic or ductile deformation. For a mathematical derivation, Google "potato radius".
The Moon has a radius of over 1,700 km. Bear in mind, also, that much of it and the Earth would have be molten material after being separated by a collision, so both would have returned to a spherical shape rather quickly.
"Common sense is the collection of prejudices acquired by age eighteen."
Albert Einstein
The world's burning. Moped Jesus spotted on I50. Details at 11.
Asteroid bombardment, vulcanism, and tectonics are the primary methods by which heavy metals accumulated on the surface. If this theory is correct some core materials could have de-orbited back to the surface as well. Either that or Aliens did it.
Knowing it all since the late 70's.
Formed by a collision? That's absolute nonesense... The moon is a deity that is to be worshiped! Bill o' Reilly told me so!
I know what you mean, it's as if an invisible force formed the moon into an almost perfect sphere.
I feel obliged to point out that isotopic fractionation is not "central" to carbon dating. The key to carbon dating is that radioactive carbon-14 decays to nitrogen-14 with a half life of roughly 5700 years, enabling biological material to be dated by its residual carbon-14 content. That is not isotopic fractionation, it's radioactive decay. Isotopic fractionation would be involved if you observed a difference in the ratio of carbon-12 to carbon-13 in plants versus that same ratio in the air.
Heck! Ralph Kramden offered trips for free in the 50s.
Laissez lire, et laissez danser; ces deux amusements ne feront jamais de mal au monde. - Voltaire
I'm not trolling, I'm really interested about this. STOP BEING SO PARANOID!!!
And thanks for the link.
Cheers
We don't have to exercise ourselves that much to know, actually - just check the headlines at the time. The Guardian puts it most succintly:
Earth hit by huge asteroid, creates moon
And from The Sun:
Rooney injured by space rock
Sorry, it was such a basic question from my perspective, to which the answer is readily and widely available since... forever, so I thought wrongly of it.
...gis sdrawkcab (usually not responding to ACs; don't bother posting as AC)
Fry: That's not an astronaut, it's a TV comedian! And he was just using space travel as a metaphor for beating his wife.
They do sample rocks from various asteroids, doing isotope comparison on those, and have some idea of the chemical composition of rocks on some of the inner planets. They are all similar, but also clearly different as there are gradients observed in the proportion of elements when increasing distance from the sun. There is actually a rather large difference between many asteroids and the surface of the Earth due to Earth's size allowing for more separation of elements.
So, while they all might be similar, they are not all similar to the same degree. This is like looking at how similar DNA is. Chimps and humans are similar like the Moon and Earth. While asteroids and Mars might be similar too, as are mammals are similar to humans too, that doesn't mean chimps and all mammals look the same in DNA analysis because they are both similar to some degree to humans.
and you're a troll because you link to a site which talks of "the nine planets"?
Also FatPhil on SoylentNews, id 863
yes, but we forgive you.
THINK! It's patriotic
Oh noez, I have been CAUGHT!
...gis sdrawkcab (usually not responding to ACs; don't bother posting as AC)
You've not got away with it - I have reported your MAC address to the Internet Central Administation Bureau!
Also FatPhil on SoylentNews, id 863