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Moon Younger Than Previously Thought
TaeKwonDood writes "Analysis of a piece of lunar rock brought back to Earth by the Apollo 16 mission in 1972 has shown that the Moon may be much younger than previously believed. Researchers say that the findings allow for one of two possibilities: the moon is 200 million years younger than previously thought, or the theory that the moon used to be a molten ocean is wrong."
God just made it that way. He's God. He's makes moons however he wants.
Please, no "that's no moon" jokes this time. It's getting old. Not as old as previously thought, but still damn old.
You see? You see? Your stupid minds! Stupid! Stupid!
TFA says: Once we removed the contamination, we found that this sample is almost 100 million years younger than we expected," says researcher James Connelly of the Centre for Star and Planet Formation.
Come on /., doesn't anybody verify facts / articles anymore ??
From the article:
The team analysed the isotopes of the elements lead and neodymium to place the age of a sample of a FAN at 4.36 billion years. This figure is significantly younger than earlier estimates of the Moon’s age that range to nearly as old as the age of the solar system itself at 4.567 billion years.
So when they say 200 million years younger, that means 4.3 byr instead of 4.5 byr. I'm sure this is interesting to those in the field, but I don't think that counts as "much younger".
It's not about atoms. It's about how solids are created. If you take a steel allow and look at it using a metallurgical microscope you can see it's made of many really small crystals (grains). How the atoms are organized into those grains is a function of many things, including the cooling rate. So, the scientists probably looked into the rock micro structure (the grains) and calculated a cooling rate for them. I didn't read the article but many, many, many years ago as a metallurgy student I had an interest into iron meteorites.
English is not my first language. Corrections and suggestions are welcome.
I swear, officer, she told me she was 4.567 billion years old!
Well, some lighter elements can be converted to other elements as a result of being bombarded by cosmic rays (it's one of the methods of telling how long rocks have been exposed to the surface on the Earth, as you can't exactly radiocarbondate rock). So stuff that's on the surface of the moon - even stuff that's nominally been there for 4 billion years - may not be the same as it was 4 billion years ago.
Compounds are more complicated. The updated theory for the moon's formation is that it is the gelling together of two smaller moons that formed when the Earth was struck by a planetoid about the size of Mars. Anything that dates back to the original two smaller moons will clearly be older than that material which formed due to the energy of the collision. Further, as smaller masses radiate heat faster than larger masses and the two original moons are theorized to have been different sizes, rocks from the larger original moon will show a younger age from rocks from the smaller original moon.
And, yes, there have been plenty of impacts from space debris. One was so massive that observers on Earth recorded that the moon appeared to have horns. Since that was in historic times, we can assume that similar-sized collisions have happened in times before observers. Energies large enough to create light visible from Earth are going to be great enough to change the date of the rock in the area.
Then there's another complication. Rock is not just one super-crystal but a solidified soup of many compounds - and, in some cases, a solidified mix of distinct rocks that got cemented together. The age of the compounds may be very different from the time of solidification. (Mudstone, for example, isn't considered as old as the mud from which it formed.)
Obviously, NASA isn't stupid. They are going to make sure that they use appropriate methods. After all, the wrong method would be just like mixing feet and meters, or wiring a magnetic sensor upside-down. (Seriously, even though they have done some stupid things, they probably are using the correct method here. However, because of the update to the theory on the moon's formation - having two precursor moons of different age colliding at slow speed, I am not necessarily convinced by their interpretation. I am not convinced the theorists are communicating as well as they need to.)
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
It is my understanding that the surface is composed of meteorites that hit long after the core formed. Dating the surface should not give you the age of the moon as a whole unless it's uniform in composition. If you do the same to date the Earth, then creationists will have plenty more fuel to support their story.