Meteorites That Made Earth Are Of Many Types, Geochemists Report

By: Clara Moskowitz
Published: 03/01/2012 02:31 PM EST on SPACE.com

Earth's building blocks were more eclectic than once thought, according to a new study suggesting our planet formed from collisions of many different types of meteorites.

Our planet is thought to have formed around 4.5 billion years ago from a disk of dust grains left over from the cloud of material that built our sun. These grains slowly clumped together, drawn by gravity into pebbles, then boulders, then planetary embryos. Eventually, enough mass coalesced to form the planet Earth.

Scientists had thought that most of the bodies that merged to make Earth formed from a narrow zone in space and were similar to each other, belonging to a subclass of meteorites called enstatite chondrites. This idea was based on measurements of numerous striking similarities between different types of atoms (called isotopes) of elements such as oxygen, nickel and chromium, between the Earth and enstatite chondrites.

But a new study of the silicon isotope signature of Earth rock samples and meteorites suggests that Earth is made of a more diverse mix of meteorites. [The Solar System To Scale (Infographic)]

Geochemists Caroline Fitoussi and Bernard Bourdon of the Ecole Normale Supérieure de Lyon in France analyzed the silicon isotopes in terrestrial rock samples collected from diverse types of mantle rocks. They also analyzed lunar rock samples collected by NASA astronauts on moon missions. They compared these to meteorite samples, particularly enstatite chondrites and another type called enstatite achondrites. The measurements were done at the Swiss Federal Institute of Technology of Zurich in Switzerland.

Using computer models of Earth's formation, the researchers calculated that a mix of three types of meteorite ingredients could have produced the right blend of oxygen, nickel, and chromium isotopes previously measured in Earth samples, as well as their new findings about silicon isotopes in terrestrial and meteorite samples. The results suggest that a mixture of chondrites, rather than enstatite chondrites alone, probably combined to create the Earth.

"This is the first time that a different composition in isotopes is observed for a major element between the enstatite chondrites and the Earth," Fitoussi told SPACE.com. "So that's quite different from what has been observed before."

The fact that the silicon isotope compositions measured were similar in both the Earth and moon rock samples suggests that the material that formed the moon must have mixed with the Earth's mantle before the moon formed so that both bodies hold the same signature.

"That should tell us something about how the moon really formed and what are the constraints," Caroline Fitoussi said.

The moon is thought to have resulted when a giant asteroid slammed into the Earth not long after our own planet's birth. But the precise details of the process are still not well understood.

The new findings were published in the March 2 issue of the journal Science.

You can follow SPACE.com assistant managing editor Clara Moskowitz on Twitter @ClaraMoskowitz. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

• Top 10 Extreme Planet Facts
• The Top 10 Views of Earth From Space
• 5 Reasons to Care About Asteroids

Copyright 2012 SPACE.com, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

WATCH: WHAT ELSE CAME FROM METEORITES?

Comments

[iLdoRight]

01:51 AM on 03/20/2012

Has everyone checked to see if they could find the "Made in China" tag on it?

[CSKAP]

12:25 PM on 03/06/2012

Golly gee whillikers, there seems to be quite a few of them college educated “snobs” here commenting, using all that “reason” and “facts” and such.
Once Pope Ricky is elected, we’ll put an end to all this!!
(Sorry about the no CAPS to really reinforce my words but I did use the exclamation points at least)

[kennethhdeome]

09:46 PM on 03/05/2012

I'm not religious whatsoever, but as a philosopher I feel it pertinent to point out that trying to prove the ethereal doesn't exist through scientific means is like trying to disprove the existence of ice by driving through the desert.

[Warning: Non scientific “theory” ahead.]

Besides, everyone knows if you disassociate nothingness you get negative infinity, zero, and positive infinity.

These translate to space, unincorporated dimensional filaments, and (light or hot) matter/energy.

The Big Bang occurred because repeated compression, explosion and rebound back to compression (bouncing) eventually bore gravity as an extraneous form of energy, with so-called attractive forces actually being pressure from surrounding nothingness, which gravity then overpowered.

Since the law of conservation of energy was not yet established, faster than light expansion was possible, at least until matter/energy and gravity became fully associated, causing 360 degree expanding instances of “mattergy” to affect each other universally, in effect putting the brakes on.

The way I see gravity is it allows matter to move through stagnant space via sub-atomic jumps between dimensional filaments (really, really fine strings) that do not in any way, shape or form come into contact with each other.

Time, normally seen as intertwined with dimensions, is itself relegated to result, not cause, meaning the effects of time are

[continued]

[kennethhdeome]

09:46 PM on 03/05/2012

[conclusion]

associated with the forces of gravity and subsequent movement of matter through space, rather than a force acting upon matter directly.

And since gravity pushes its way through space, the vacuum effect normally credited to gravity must have another source, which may be dark mattergy, since nothingness continues to disassociate, only since the Big Bang there is no heat to form hot matter or space, only “filler” which may be why celestial bodies are moving apart.

Basically, all matter is suspended within space and space is still “surrounded” by nothingness, meaning given the number line example above, we would have to rearrange said scale to read “zero, negative infinity, positive infinity”, since space lies between mattergy and nothingness.

Now picture the planet Earth spinning around its axis while orbiting the sun while orbiting the galactic center, and imagine Earth’s every particle moving through space in proper order by sliding down the length of the accorded dimensional (x,y,z) filament then “jumping” perpendicularly to the next accorded filament in keeping with the law of conservation of energy.

See what happens when you watch a program on the Big Bang and then start wondering what happened before that event?

[kennethhdeome]

11:29 AM on 03/07/2012

P.S.

Think of the interior of the so-called cosmic egg, which is merely what I refer to as less than zero and more than zero surrounded by nothingness, as a mirror/inverse of our universe: Highly compressed, with like materials attracting and dislike repelling, thus placing early matter at the core with a strong bond and early space forced into a shell around it with a weak bond.

In essence, since matter/energy and space can neither be destroyed nor created, they must comprise nothingness if combined, as would happen inside a black hole, for example.

So our universe is simply the basic building blocks of nothingness with a little resistance added at the beginning allowing for some cooking to occur.

After all, we exist because the Big Bang slowed, cooled, and formed stars--which are big, dense ovens.

[iLdoRight]

02:00 AM on 03/20/2012

Didn't you overlook the "God is a Butterfly effect"?

[Zaida Adams]

07:22 AM on 03/05/2012

I recommend a youtube doco called THE LAST DAY OF THE DINOSAUR which is an excellent watch if you're keen on seeing the effects of a catastrophic collisions. It goes for over an hour, but was a great and informative watch.

[Devout Skeptic]

05:38 PM on 03/04/2012

This a great video. I has little to do with the article but is quite relevant to a lot of the discussion & questions people had in the comments.

http://www.youtube.com/watch?v=7ImvlS8PLIo

[CabinAgue]

06:33 PM on 03/04/2012

Seconded!  I watched this for the first time a few nights ago, and agree with your recommendation.

[Galaxie]

06:39 PM on 03/04/2012

Thxs!

[Joel Grizzel]

12:32 PM on 03/04/2012

I thought it was another planet that hit earth that caused debris to spin off and became the moon and this has been born out as well by mathematical modeling. An asteroid did not work in the models.

[cre8iveman]

12:35 PM on 03/04/2012

May be a little bit about semantics. Giant asteroid, planetoid, moon, all refer to approximately the same kind of large celestial body.

[palindrom]

09:24 PM on 03/04/2012

You thought right -- that's the prevailing theory. The impactor must have been about the size of Mars!

[CelticDragon]

11:02 PM on 03/04/2012

Yep. My petrology professor called it "The big whack" and it was big enough to actually melt the entire planet so that the light silicates migrated to the surface to form the crust and the heavier elements went towards the center. Before the collision, the Earth was a more of less homogenous aggregate of debris. The collision actually is responsible for making Earth capable of supporting life, since a rotating iron core gives us the magnetic field we need to keep out the worst of the harmful effects from the sun.

[an seanchus mor]

11:29 AM on 03/04/2012

ah I think that was planetesimal rather than asteroid

[Darkingz]

06:01 AM on 03/05/2012

yup you are right. Look up Theia!

[an seanchus mor]

08:53 AM on 03/05/2012

Thanks dz, I just did and never knew why the planetesimal was named Theia (or thought about it too much for that matter)
I specifically refer to it as a planetesimal rather than planet as Theia part-coalesced with the pre-existing planetesimal which became the earth as we have it now, even though its generally hypothesised that Theia collided with Earth.
Pedanticism gets me in trouble a lot!

Theia was a Greek titan and was also called Euryphaessa which means ‘wide-shining’ or ‘the far shining one’, probably an apt description for an approaching planetesimal if you could have been around to look up just before impact.
Theia also seems to be the mother of the moon goddess!

I got this of wikipedia
http://en.wikipedia.org/wiki/Theia

well named indeed!

[CabinAgue]

08:51 PM on 03/03/2012

Michael L is back, and with MORE capitalized words and LOTS of exclamation points!  Because nothing is MORE convincing!

[ProudToBeVeryLiberal]

08:57 PM on 03/03/2012

I liked your attempt to mock ML. Unfortunately it disappeared for the very same reason most of his comments do. And it's hilarious to see that he keeps trying and he doesn't realize why he isn't getting through.

Priceless.

[CelticDragon]

10:43 PM on 03/04/2012

Nice to see you again!! :) I am graduating in May with my degree in geology from Guilford College!!

[davyjones2112]

09:02 PM on 03/03/2012

This should prove quite amusing !

[ProudToBeVeryLiberal]

08:32 PM on 03/03/2012

The same people who state that there's no evidence for the Big Bang --incidentally, just because they aren't aware of it-- believe in a god who created himself.

You've got to love the irony...

[HarleyOpenRoad]

08:42 PM on 03/03/2012

No, Christians have never believed in a "god" who created himself.

[ProudToBeVeryLiberal]

08:43 PM on 03/03/2012

So, who created god. Another god? And who created the other god?

[CabinAgue]

08:57 PM on 03/03/2012

My snarky reply vanished. :(

[ProudToBeVeryLiberal]

09:12 PM on 03/03/2012

You have no idea how many of ML posts are hitting the wall. I can see it on the side panel, now being his exclusive territory. He has started calling me all sorts of names.

I guess a smart woman is what his iIk fears the most... Maybe an openly g.a.y man could take some of that pressure, better if bIack or Hispanic... ;)

[Miranda Wrietz]

06:32 PM on 03/03/2012

You've been told that "evolution is just a theory", a guess, a hunch, and not a fact, not proven. You've been misled. Keep reading, and in less than two minutes from now you'll know that you've been misinformed.

The Theory of Evolution is a theory, but guess what? When scientists use the word theory, it has a different meaning to normal everyday use.1 That's right, it all comes down to the multiple meanings of the word theory. If you said to a scientist that you didn't believe in evolution because it was "just a theory", they'd probably be a bit puzzled.

In everyday use, theory means a guess or a hunch, something that maybe needs proof. In science, a theory is not a guess, not a hunch. It's a well-substantiated, well-supported, well-documented explanation for our observations.2 It ties together all the facts about something, providing an explanation that fits all the observations and can be used to make predictions. In science, theory is the ultimate goal, the explanation. It's as close to proven as anything in science can be.

Some people think that in science, you have a theory, and once it's proven, it becomes a law. That's not how it works. In science, we collect facts, or observations, we use laws to describe them, and a theory to explain them. You don't promote a theory to a law by proving it. A theory never becomes a law.

[Dbos]

06:57 PM on 03/03/2012

You listened in school.F&F

[ProudToBeVeryLiberal]

06:59 PM on 03/03/2012

Yes, exactly why I said these people don't understand how science works.

[Miranda Wrietz]

07:05 PM on 03/03/2012

And you are very correct. And it is through ignorance. Most people are taught the difference in a scientific " theory" and a "law" in high school. This is willfully ignoring actual facts and science, not just misunderstanding. I keep asking if these folks deny natural selection. And if so, are they going to forego the new anti-microbial treatments for the the strains of microorganism that have EVOLVED immunities.

[PoloniumMan]

09:36 PM on 03/03/2012

They also like to attack Darwin, which is a bit like arguing against quantum mechanics, but going no further than Rutherford's plum pudding model of the atom.

[ProudToBeVeryLiberal]

06:04 PM on 03/03/2012

I don't know why this was removed, but I'll post it again.

Science is questions that may never be answered.
Religion is answers that may never be questioned.

[Galaxie]

07:12 PM on 03/03/2012

Excellent!

[wowme]

07:18 PM on 03/03/2012

That's why I don't believe in any with certainty.

[cre8iveman]

02:30 PM on 03/04/2012

Even your own existence?

[Galaxie]

04:49 PM on 03/03/2012

“Extraordinary claims require extraordinary evidence.”
― Carl Sagan

[davyjones2112]

05:03 PM on 03/03/2012

mentioning Carl, gets you a fan.

[Galaxie]

05:04 PM on 03/03/2012

Thxs!

[lookbuzz]

05:00 PM on 03/06/2012

F & F'd!

[Galaxie]

04:47 PM on 03/03/2012

“Atheism is more than just the knowledge that gods do not exist, and that religion is either a mistake or a fraud. Atheism is an attitude, a frame of mind that looks at the world objectively, fearlessly, always trying to understand all things as a part of nature.”
― Carl Sagan

[palindrom]

06:07 PM on 03/03/2012

I like that.

Met the man once. He was very gracious in person.

[Galaxie]

07:09 PM on 03/03/2012

I would have like to have met him!

[cre8iveman]

12:45 PM on 03/04/2012

Actually, as much as I admired Sagan, the word Pantheism would be a better term in this case. Unless this is a typo.

[Rodger leMonde]

03:55 PM on 03/03/2012

When those of faith decry science as against religion they limit their God to their own understanding of God. The processes that have been learned of physics and life are far more intricate and amazing than the Biblical account of a being magically saying "make it so". There are more than a few scientist that seek to know God by exploring the creation in all it's magnitude.

[Dezembrr]

04:01 PM on 03/03/2012

Excellent point!

[ProudToBeVeryLiberal]

04:19 PM on 03/03/2012

"I do not believe in a personal God and I have never denied this but have expressed it clearly. If something is in me which can be called religious then it is the unbounded admiration for the structure of the world so far as our science can reveal it."

-- Albert Einstein, 1954