NASA Research Team Reveals Moon Has Earth-Like Core
WASHINGTON – State-of-the-art seismological techniques applied to Apollo-era data suggest our moon has a core similar to Earth’s.
Uncovering details about the lunar core is critical for developing accurate models of the moon’s formation. The data sheds light on the evolution of a lunar dynamo — a natural process by which our moon may have generated and maintained its own strong magnetic field.
The team’s findings suggest the moon possesses a solid, iron-rich inner core with a radius of nearly 150 miles and a fluid, primarily liquid-iron outer core with a radius of roughly 205 miles. Where it differs from Earth is a partially molten boundary layer around the core estimated to have a radius of nearly 300 miles. The research indicates the core contains a small percentage of light elements such as sulfur, echoing new seismology research on Earth that suggests the presence of light elements — such as sulfur and oxygen — in a layer around our own core.
The researchers used extensive data gathered during the Apollo-era moon missions. The Apollo Passive Seismic Experiment consisted of four seismometers deployed between 1969 and 1972, which recorded continuous lunar seismic activity until late-1977.
“We applied tried and true methodologies from terrestrial seismology to this legacy data set to present the first-ever direct detection of the moon’s core,” said Renee Weber, lead researcher and space scientist at NASA’s Marshall Space Flight Center in Huntsville, Ala.
In addition to Weber, the team consisted of scientists from Marshall; Arizona State University; the University of California at Santa Cruz; and the Institut de Physique du Globe de Paris in France. Their findings are published in the online edition of the journal Science.
The team also analyzed Apollo lunar seismograms using array processing, techniques that identify and distinguish signal sources of moonquakes and other seismic activity. The researchers identified how and where seismic waves passed through or were reflected by elements of the moon’s interior, signifying the composition and state of layer interfaces at varying depths.
Although sophisticated satellite imaging missions to the moon made significant contributions to the study of its history and topography, the deep interior of Earth’s sole natural satellite remained a subject of speculation and conjecture since the Apollo era. Researchers previously had inferred the existence of a core, based on indirect estimates of the moon’s interior properties, but many disagreed about its radius, state and composition.
A primary limitation to past lunar seismic studies was the wash of “noise” caused by overlapping signals bouncing repeatedly off structures in the moon’s fractionated crust. To mitigate this challenge, Weber and the team employed an approach called seismogram stacking, or the digital partitioning of signals. Stacking improved the signal-to-noise ratio and enabled the researchers to more clearly track the path and behavior of each unique signal as it passed through the lunar interior.
“We hope to continue working with the Apollo seismic data to further refine our estimates of core properties and characterize lunar signals as clearly as possible to aid in the interpretation of data returned from future missions,” Weber said.
Future NASA missions will help gather more detailed data. The Gravity Recovery and Interior Laboratory, or GRAIL, is a NASA Discovery-class mission set to launch this year. The mission consists of twin spacecraft that will enter tandem orbits around the moon for several months to measure the gravity field in unprecedented detail. The mission also will answer longstanding questions about Earth’s moon and provide scientists a better understanding of the satellite from crust to core, revealing subsurface structures and, indirectly, its thermal history.
NASA and other space agencies have been studying concepts to establish an International Lunar Network — a robotic set of geophysical monitoring stations on the moon — as part of efforts to coordinate international missions during the coming decade.
For more information about NASA science exploration missions, visit:
http://www.nasa.gov/topics/moonmars
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So they used the data from seismographs that had been placed on the moons surface during the Apollo missions. Could it be – I mean is it possible – that the ‘moon landing was faked’ people were plain wrong?
Liked your post Hoser. Sadly, in some ways, it appears that we’re in the dark ages, science has become more of a religion than religion, kids who do well in school are outcast, and the greatest leaps to occur relate to social networking, gaming, and weapons.
Interesting stuff. I wonder if there is any trace that the Moon’s core once acted like a dynamo to produce a magnetic field. The absence of a rotating iron core on Mars is supposed to be why it lost its atmosphere to space, although ridiculously large volcanoes and evidence of a LOT of liquid surface water argue that Mars was considerably different the husk it is today.
Perhaps so was the Moon.
Despite the “state-of-the-art” in the headline, this is actually old data analyzed by old methods. Various forms of signal stacking have been used ever since we’ve had ears.
Imagine cavemen: “Og. I hear big critter coming. Og put ear to ground, tell me Og hear same thing or not same thing.”
The only new part: fast computers make it vastly easier and cheaper.
Therefore I’m inclined to trust this study far more than anything using post-1975 data or digital modeling methods.
The Apollo programme was at the very edge of technology, infact over the edge. The potential benefits of the programme (mainly political?) were outweighed by the risks of losing astronauts, especially leaving two stranded on the lunar surface, with not even a vague glimer of a chance of rescue, condemned to suffocation.
I wonder if anyone has thought to test for oil in the moon ? As a confirmation of abiotic theory. Some Russian scientists might be most inclined in that direction.
brant says:
January 8, 2011 at 6:47 pm
“This work still involves simulations. If you take the data and compare to known phenomena experiments, this is what you come up with.
Hollow Moon?”
Engineering strength of materials would suggest that the weight of the lithosphere would crush, stope and fill the void if the material was solid. If plastic, it would flow in to fill the void and probably make for some interesting “basin and range” surface topo.
Rhoda R says:
January 8, 2011 at 5:58 pm
I hope this isn’t just another NASA ‘modeling’ exercise because they need to be doing some real science to regain their standing.
————
Yes it us another modelling exercise.
But let me help you get over your model-
phobia.
A few years back a guy did some historical research and became interested in comets. He used the new fangled Newtonian theory of gravitation, constructed a model and calculated the expected return date of the comet. The comet appeared at the calculated time.
The guy was of course Halley. Scientists and Engineers have been using models ever since.
Wanna build a microcomputer to sell to people to surf the Internet. Use a model to verify the design.
Wanna build an aircraft. Use a model.
Wanna put a rover on Mars. Use a model.
Wanna improve the placement of a heart pacemaker. Use a model.
Wanna improve the extraction of oil from a well. Use a model.
Wanna improve the efficiency of a car engine. Use a model.
Wanna control a disease out break. Use a model.
Etc., etc., etc.,
No doubt at the time there were comet skeptics. It would be amusing to see if the arguments used then followed the same patterns used on these blogs.
Semi-liquid?
Sounds like … Camembert.
Maybe green from over-aging.
mike sphar – re testing for oil in the moon.
I think it’s Titan which has the oil, our moon of interest to the Russians and others for Helium-3
http://curezone.com/forums/am.asp?i=794487
tom t says:
January 8, 2011 at 5:47 pm
Well naturally, because as we all learned from “The Adventures of Rocky and Bullwinkle” there are moonmen . . . .
My first thought on reading this article . . . gee, don’t most objects “in space” have these same similar characteristics?
Tom brought up Rocky & Bullwinckle . . . I’m of the age of the Cheech and Chong . . . and when we went to see the movie “Up in Smoke” where they talk about how solar systems are similar to atomic systems . . . never forgot it . . . funny, funny . . . and source it often . . . for more concepts than this one.
Our discussion then turned to talking about Einstein and the theory of relativity . . . and for me the formulation of the principle of . . . It’s the little things that can lead to or be the “mean” of the big things. . .
I seem to recall from one of the astronomy texts I’ve read over the last 40 years that at a certain size, gravity turns odd-shaped rocks into round ones. At a different size, the force of gravity would increase internal heat to the point where a semi-molten or molten core formed. Most stone planetary balls also contain some radioactive elements, which may also contribute to the molten core of larger moons and planets. Even Enceladus, Ganymede, Io, and Europa may have sufficient heat within their cores to affect surface conditions. I’d be very surprised if Titan did not. This data only seems to confirm what many have postulated over the past 50 or so years.