Posted on 07/08/2014 10:35:49 AM PDT by robowombat
New evidence supporting moon formation via collision of 2 planets by Staff Writers Oxford, UK (SPX) Jun 09, 2014
A new series of measurements of oxygen isotopes provides increasing evidence that the Moon formed from the collision of the Earth with another large, planet-sized astronomical body, around 4.5 billion years ago. This work will be published in Science* on 6th June, and will be presented to the Goldschmidt geochemistry conference in California on 11th June.
Most planetary scientists believe that the Moon formed from an impact between the Earth and a planet-sized body, which has been given the name Theia. Efforts to confirm that the impact had taken place had centred on measuring the ratios between the isotopes of oxygen, titanium, silicon and others.
These ratios are known to vary throughout the solar system, but their close similarity between Earth and Moon conflicted with theoretical models of the collision that indicated that the Moon would form mostly from Theia, and thus would be expected to be compositionally different from the Earth.
Now a group of German researchers, led by Dr. Daniel Herwartz, have used more refined techniques to compare the ratios of 17O/16O in lunar samples, with those from Earth. The team initially used lunar samples which had arrived on Earth via meteorites, but as these samples had exchanged their isotopes with water from Earth, fresher samples were sought.
These were provided by NASA from the Apollo 11, 12 and 16 missions; they were found to contain significantly higher levels of 17O/16O than their Earthly counterparts.
Dr Herwartz said "The differences are small and difficult to detect, but they are there. This means two things; firstly we can now be reasonably sure that the Giant collision took place. Secondly, it gives us an idea of the geochemistry of Theia. Theia seems to have been similar to what we call E-type chondrites.
"If this is true, we can now predict the geochemical and isotopic composition of the Moon, because the present Moon is a mixture of Theia and the early Earth. The next goal is to find out how much material of Theia is in the Moon".
Most models estimate that the Moon it is composed of around 70% to 90% material from Theia, with the remaining 10% to 30% coming from the early Earth. However, some models argue for as little as 8% Theia in the Moon. Dr Herwartz said that the new data indicate that a 50:50 mixture seems possible, but this needs to be confirmed.
The team used an advanced sample preparation technique before measuring the samples via stable isotope ratio mass spectrometry, which showed a 12 parts per million (+/- 3 ppm) difference in 17O/16O ratio between Earth and Moon.
Go find the planet Theia with a moon-sized chunk out of it and that would be the necessary evidence to believe this drivel.
Velikovsky Vindicated...
Theia is not believed to be missing a chunk. It is believed to be a smaller planet collided with Earth, with Theia's mass split between the Earth and Moon.
I wouldn’t call it drivel ... This theory has been around since the very late 1800s. Like true science, it takes debate, experimentation, and discussion to understand / accept or totally reject an idea. In this case, one can truly say that the science is far from settled.
I have some friends who live on a remote planet 4.5 billion light years away. They’re taking a look now through their monster telescope. They’ll give us the answer in 4.5 billion years when their light-speed message reaches us.
You should understand the theory first before you criticize it.
Good luck. I suspect it will take all the mental effort you can muster.
There is a documentary from several years ago about this theory called “If we had no Moon”. Without our lunar companion, things would be very different.
I’m gathering that that particular correspondent isn’t really into intellectual heavy lifting, if you know what I mean. ;-)
Such a collision would be a ricochet effect, right? This would result in two things:
One, the moon would be moving quickly away from the earth at many miles per second. Right now it is moving away at a few cm per year.
Two, the moon would be spinning very fast(see a ricocheting projectile). The moon does not spin. We had to get in a rocket to see the other side.
Not likely, more like a collision between two balls of clay.
It is right under your feet.
Let me be the first and hopefully the last to state that this is all Theia-retical.
Your reasoning is faulty on a couple of accounts:
1. The recoiling body would not necessarily be moving rapidly away from the earth. That would be true in the absence of any forces acting on the body. However there is one major force, gravity, acting to slow the recession of the moon. The moon in currently gravitationally bound to the earth. There would be no left over “collision velocity”.
The current recession of the moon is due to the mechanism of tidal friction. The moon’s gravity creates a tidal bulge that moves around the earth at a speed slightly different from the speed of the earth’s rotation (due to the fact that the moon changes position relative to the earth during the course of one earth rotation). This friction acts to slow the rotation of the earth. This reduces the energy of the earth. Since energy is conserved, the energy lost by the earth must appear elsewhere in the earth-moon system. It appears as an increase in the orbital energy of the moon, ie. the moon goes into a higher orbit. This has nothing at all to do with any collisional velocity; even if the moon formed in place, this would still occur. This recession will cease when the length of time needed for one rotation of the earth is equal to the length of time needed for the moon to orbit the earth.
2. The moon does in fact rotate about its axis. Indeed, if it did not, we would not see only one side of the moon; we would see ALL of the moon. The moon’s rotational period is in fact equal to its orbital period - that’s the reason only one side of the moon is visible.
Visualize it this way: go into a room where you have space to move around. Put a sign or some marking on one wall of the room. Put a lamp in the center of the room. Now, while facing the sign, walk in a circle around the lamp. Were you always facing the lamp? By always facing the sign, you ensured that you did not rotate around your axis, but in so doing you presented all sides of your body toward the lamp. Now, walk around the lamp, but this time start by facing the sign, but walk so that you are always facing the lamp. How many times did you turn so that you were facing the sign (after the starting point, obviously). If you did this right, you should have ended up facing the sign, but you should not have faced it at any other point in your “orbit” around the lamp. That indicates that you made one rotation around your axis in the time it took you to make one orbit around the lamp.
Hopefully you see the analogy to the earth-moon system and where you went wrong in your reasoning. BTW: the fact that the moon’s orbital and rotational periods are in synch like this is no accident; a very similar mechanism to the one I talked about in part 1 of my post above is at work here. The moon has a much lower mass, though, so tidal friction slows its rotation much more rapidly. Thus the moon is tidally locked, but the earth is not as yet.
(sorry for any pain that caused:))
close friends...
If so, God caused it to happen that way. Somehow I think that god didn’t need to go bowling to make the moon though.
Maybe the Almighty was in a whimsical mood. Perhaps another of the Celestial Beings had suggested bowling as a relaxing past time and the Almighty just took it to its logical conclusion.
Ah yes ... you know you have a fool-proof scientific theory when your theory actually predicts you won't find any evidence for it.
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