Posted on 05/01/2019 11:20:29 PM PDT by LibWhacker
There are a number of theories about where the moon came from. Our best guess is that it was formed when the Earth was hit by a large object known as Theia. The impact threw up huge amounts of debris into orbit, which eventually coalesced to form the moon.
There’s a problem with this theory. The mathematical models show that most of the material that makes up the moon should come from Theia. But samples from the Apollo missions show that most of the material on the moon came from Earth.
A paper out earlier this week in Nature Geoscience has a possible explanation. The research, led by Natsuki Hosono from the Japan Agency for Marine-Earth Science and Technology, suggests that the Earth at the time of impact was covered in hot magma rather than a hard outer crust.
Magma on a planetary surface could be dislodged much more easily than a solid crust could be, so it’s plausible that when Theia struck the Earth, molten material originating from Earth flew up into space and then hardened into the moon.
This theory relies a lot on the timing of the formation of the moon. The Earth would have to have been in a sweet spot of magma heat and consistency for the theory to be true.
Additionally, as Jay Melosh at Purdue University explains in a comment article alongside the research, this new simulation still doesn’t check all the boxes needed to get our lunar observations in line with our theories. But it is an important step in getting closer to a solution.
It seems passing strange that so many planets in the solar system have moons, but ours had to come from a planetary collision. Was the early system bumper cars writ large?
I’ve always heard the outer crust solidified about 4 billion years ago. But it had to have been a little more than that since geologists have radio-dated rocks to over 4 billion years.
When I was a kid, and even into my early adulthood, science never really got behind the idea that most craters were impact features and not volcanic in nature. Us ordinary mortals all laughed at what seemed to be “The Sky Is Falling” hysteria. What a bunch of Chicken Littles!
Then Eugene Shoemaker came along and finally clinched it for the impact crowd, first for many craters on Earth, then again for the Moon’s craters when he worked on the Apollo program. That was 1969. So impact theory is very, very recent. It just wasn’t accepted before Shoemaker.
I can’t for the life of me recall a theory from back then that claimed a huge magma ocean which covered the Earth splashed out into outer space after a giant impact, ultimately coalescing and cooling to become our Moon. Impact theory just wasn’t accepted before ‘69. And after that I was too interested to have missed it. Or so it seems. More details please, so I can check it out. Very interesting, thanks.
Who says you have to be a scientist to make a great discovery? Go for it!
I don’t remember impact being involved. Earth and the moon are both too circular for I oscar to be involved.
What I remember is an illustration of the lava ball breaking from the earth and becoming the moon.
Both earth and moon were molten at the time.
“Was the early system bumper cars writ large?”
Sure was, if you believe Immanuel Velikovsky. Not even all that early.
I remember him.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.