SoylentNews is people
SoylentNews
Scientists have long assumed that all the planets in our solar system look the same beneath the surface, but a study published in Geology on Oct. 4 tells a different story.
"The mantle of the earth is made mostly of a mineral called olivine, and the assumption is usually that all planets are like the Earth," said Jay Melosh, a professor of earth, atmospheric and planetary sciences at Purdue University, who led the study. "But when we look at the spectral signature of rocks exposed deep below the moon's surface, we don't see olivine; we see orthopyroxene."
Around 4 billion years ago, an asteroid collided with the moon and created the largest and deepest impact on the moon: the South Pole-Aitken basin. The collision exposed lunar mantle in the basin and splashed up material onto the far side of the moon.
Melosh's group used remote sensing to identify what minerals compose the splashed-up material. When sunlight hits the moon, it interacts with materials on the surface; because different materials absorb different wavelengths of light, researchers can tell what materials are on the surface by looking at the reflected signal.
Wallace and Gromit will be disappointed to learn it's not Stilton.
South Pole–Aitken basin ejecta reveal the Moon's upper mantle (DOI: 10.1130/G39375.1) (DX)
(Score: 4, Touché) by FatPhil on Friday October 06 2017, @07:37AM (5 children)
Have they? Why? Given that they look wildly different on the surface, wouldn't Ockham dictate that being different below the surface was more likely? Weren't things like reports of methane-spewing ice volcanos enough of a hint to dispel the myth that the wanderers out there aren't all alike deep down.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 4, Funny) by c0lo on Friday October 06 2017, @07:49AM (2 children)
Now it's a true statement.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 1) by khallow on Friday October 06 2017, @12:06PM (1 child)
(Score: 2) by c0lo on Friday October 06 2017, @12:27PM
Thanks for the styling suggestion, sounds better indeed. But...
If we'd be speaking of a single journalist, I wouldn't mind. Trouble is I'm seeing it frequently enough lately to make a blanket generalization and apologize in the rare cases I'm wrong.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Friday October 06 2017, @01:05PM (1 child)
Well, according to the summary, one of them is
Although I suspect when he said "all planets" he didn't really mean "all planets", as he surely didn't ever consider the interior of Jupiter to be even remotely like the interior of Earth.
(Score: 2) by bob_super on Friday October 06 2017, @07:13PM
It's indeed not absurd that planets which just randomly agglomerated nearby portions of the same primordial disk of matter would have a related composition.
The disk itself didn't have to be homogeneous, but it's quite likely that it was locally consistent in its composition.
(Score: 1, Funny) by Anonymous Coward on Friday October 06 2017, @02:56PM
Now it should be. "When the moon hits your eye like a big pizza pie, that's orthopyroxene?"
With apologies to Warren and Brooks [wikipedia.org].
(Score: 0) by Anonymous Coward on Friday October 06 2017, @03:01PM (3 children)
I thought it was. Isn't it why the US moon rocks have the same composition as Earth rocks? Just asking...
(Score: 2) by Taibhsear on Friday October 06 2017, @03:21PM (2 children)
That's one of the prevalent theories, yes. Proto-Earth and Theia collide to make Earth and Luna.
http://nautil.us/blog/the-genetics-of-the-earth-and-moon [nautil.us]
(Score: 2) by HiThere on Friday October 06 2017, @05:23PM (1 child)
I thought that in that theory the Moon was largely built out of Theia bouncing off the Earth after the non-elastic collision. So while much of the surface of the Moon would be from Earth, the interior would be nearly pure Theia.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 2) by Taibhsear on Friday October 06 2017, @08:18PM
Could be a variation on that theory. In the link I posted it says around 10-40% of the moon's mass is from Pre-Earth and the rest is from Theia.
This link explains further. The collision basically disintegrated/vaporized/liquified Theia and ejected it. It then coalesced/formed into the moon. There's competing theories for what happened after that because one side of the moon has a thicker crust.
http://www.slate.com/blogs/bad_astronomy/2014/07/01/the_moon_s_two_faces_why_are_they_so_different.html [slate.com]
(Score: 2, Insightful) by Muad'Dave on Friday October 06 2017, @06:34PM
That's Wensleydale, you Philistine!
(Score: 0) by Anonymous Coward on Friday October 06 2017, @06:41PM
They throw that number around like it's nothing. That's very big assumption they're making.