Glass From Nuclear Test Site Shows the Moon Was Born Dry (newscientist.com) 48
An anonymous reader quotes a report from New Scientist: We can't recreate the giant impact that led to the moon's formation in a lab, but humans have made some other big explosions. By examining residue from the first detonation of a nuclear weapon, researchers have cracked a window into the moon's past. On 16 July 1945, the U.S. army detonated a nuclear weapon for the first time in an operation codenamed Trinity (see photo, above). As the bomb exploded with an energy equivalent to 20 kilotons of TNT, the sand underneath it melted, producing a thin sheet of mostly green glass dubbed trinitite. The explosion brought the area around the bomb to temperatures over 8000 C and pressures nearing 80,000 atmospheres. These extreme conditions are similar to those created as the moon formed in a colossal collision between Earth and another rock, probably about the size of Mars. Fortunately for planetary science, scientists meticulously measured and recorded the details of the Trinity detonation, so there is plenty of information to work with. Day and his colleagues took advantage of that past precision to investigate why the moon has surprisingly little water and other volatiles with a relatively low boiling point -- much less than Earth. To do so, they studied the distribution of one volatile element, zinc, in trinitite collected at different distances out from the explosion's center. They found that the closer to the explosion the trinitite formed, the less zinc it had, especially when it came to zinc's lighter isotopes. That's because these evaporated in the intense heat of the explosion, while the heavier isotopes didn't and so remained in the trinitite. The ratios of different forms of zinc left behind in trinitite showed remarkable parallels to what was observed in the moon rocks retrieved in the Apollo missions. This means that zinc and other volatile elements, most notably water, probably evaporated off the moon while it was being formed in a violent collision or soon afterward, while its surface was still incredibly hot. The study has been published in Science Advances.
That's weird. (Score:3)
I always assumed it had a placenta.
Presumably, the current Earth was also born dry. (Score:5, Insightful)
I've often heard that colonists to the Moon or Mars could generate much of the energy and oxygen they need if they can find water present. How much water is still present in the interplanetary environment, and is it enough to consider using it to augment the fuel/oxygen supply on an interplanetary rocket?
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I keep hearing comets being described as mostly rock and ice. I think there's water on these celestial bodies, but we aren't finding it on the surface for obvious reasons stated above.
Most places on Earth require drilling at least 100ft before finding fresh useable water where there's not natural springs. Lets send a serious drill to some of these celestial bodies and do some real digging to find out what's below. Blowing craters in the surface will just melt, then disperse water as ice, recreating the envi
Re: Presumably, the current Earth was also born dr (Score:1)
This is about water, not fresh water, in the majority of cases your drill will sink in the stuff. Earth is not short of water.
A lot of the times for fesh water it depends when you drill and in the far north and south it's 0.0000001 inches always. The rest, depends on the last time it rained.
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Depends on the ambient pressure (Score:3)
Planets start forming as cold dust with all the water-ice evenly distributed in 3D. Pressure builds progressively as the temperature also rises. The water, by enlarge, stays trapped throughout as a liquid - only slowly escaping to the surface. If the surface is too cold then it'll freeze again as it rises.
I predict The Moon, like The Earth, will have plenty of water below deck.
"by and large" (Score:2)
Dang. O_o
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By and large.
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It may well be that scientists already had a good grasp of the mineral content of the moon, they simply wanted to establish why.
Crust or mantle (Score:1)
Did part of the mantle get blown off to make the moon or it all crust?
James P. Hogan was right! (Score:2)
Nuclear explosions on the moon... Inherit the Stars explains it well. :)
re: Glass From Nuclear Test Site Shows the Moon Wa (Score:5, Interesting)
Good Grief. Talk about a bit of over-simplification - - -
article quote - probably evaporated off the moon while it was being formed in a violent collision or soon afterward, while its surface was still incredibly hot.
There WASN'T any MOON surface to evaporate from - it was the multi-quadrillion PIECES that got thermally blasted, and lost all of their volatiles.
Because the major mass-locus was earth, the free-floating material preferentially 'gravitated' here, leaving the particulate residue to accumulate into our moon, with the majority of it's material probably being from the crustal region of the earth and the colliding planetoid (Theia).
With the earth being more massive, and presumably less heated by the collision, the lighter materials would eventually either be 'lost in space' or captured by earth, while the nascent moon cloud, still in it's infancy and HOT, and in FRAGMENTS, continued to out-gas. Even with thermal equivalence of the two bodies, the higher gravitational tug of earth would have preferentially attracted - and kept - the lighter volatiles blown off by the collision. (Yep, I'm agreeing with the author, except on the point of "the moon's surface").
OK, so I'm knit-picking, but please keep your presentation straight, as there was NOT any definable 'surface' of the moon at that period, just a LOT of really hot pieces that thermally expelled all low-temp volatiles as they circled earth and eventually coalesced into our moon.
Still, overall, a very good piece, and worthy of inclusion under the 'real science' category of slashdot's potpourri - unfortunately a small and decreasing category of material on this site.
cheers . . .
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Good comment; agree.
But while we're picking nits....
https://en.wikipedia.org/wiki/... [wikipedia.org]
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lol - been there, done that. My niece brought home some of these 'guests' from school, and we bought the local family pharmacy out of RID to clean the house (and us) - - - NOT a fun day.
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Pro tip: lice in many areas have become virtually immune to over-the-counter remedies, but are still highly susceptible to benzyl alcohol, which is topically harmless to humans (and used in IV fluids, so also harmless to humans internally in certain concentrations).
5% benzyl alcohol lotion is available under the brand name Ulesfia (and maybe some other names, not sure?) in the USA, but requires a prescription. However, it is basically just benzyl alcohol mixed with creamy baby oil. (CREAMY baby oil, the t
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Is this how to make awesome crystals at home?
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There WASN'T any MOON surface to evaporate from - it was the multi-quadrillion PIECES that got thermally blasted, and lost all of their volatiles.
Wouldn't there necessarily have to have been some larger chunks that didn't get pulled into Earth? Fragments of Earth or the impactor itself?
There had to have been something fairly substantial around which Luna could coalesce. Otherwise Earth would have (a) ring(s), and not a moon. This seems to follow because Luna really is too big for its planet in the first place. Everywhere else in the solar system where moons coalesced out of a cloud of relatively small particles, those moons are considerably small
Veritasium ... (Score:2)
https://www.youtube.com/watch?v=hbXDLKFkjm0
An early success in the teetotallers campaign then (Score:2)
;)
Water boils in a vacuum (Score:2)
And ice can also quickly sublimate in a vacuum depending on the temperature, and during the day the Moon temperature rises above the boiling, let alone melting point of water. The Moon's gravity is too low to retain water vapor, so as soon as you get liquid water it disappears within minutes. Meters of ice would sublimate in a day. If the Moon had a 3 km thick layer of ice, like we do, it would sublimate in 10 years.
You don't need heat or impacts, just some basic knowledge of thermodynamics.These well-known
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Your explanation has nothing to do with thermodynamics, but alas ...
Here: http://nssdc.gsfc.nasa.gov/pla... [nasa.gov]
We kniw since nearly ten years, that there is water ice on the moon.
Elements (Score:5, Funny)
This means that zinc and other volatile elements, most notably water, probably evaporated off the moon while it was being formed in a violent collision or soon afterward, while its surface was still incredibly hot.
Ok, we all know water is an element, but isn't zinc a compound of earth and air?
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What are you taking about? Zn is a metallic element with an atomic number of 30; the first element in group 12. Didn't you ever take a carbon-zinc battery apart? You get a zinc can (anode), a carbon rod (cathode), and a bunch of yucky pasty electrolyte.
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Don't make me explain the joke.
Or maybe (Score:1)
Water came to Earth after the Moon formed. Remember it was 4.5 billion years ago when the solar system hadn't yet been formed and stable and it had a lot of dust.
Or maybe there was no collision at all, and Moon and Earth formed independently from the same rocks orbiting the Sun.
Bizarre reasoning (Score:2)
At a nuclear test site, volatiles boil off and condense farther away from the center of the explosion. Fine.
However, this has basically zilch to do with the formation of the moon. *That* impact literally knocked the earth into pieces. Likely there really was no more "center" of the impact. Also, note the quality of the science reporting: "volatile elements, most notably water". Who knew that water was an element?
The actual article [sciencemag.org] is basically only about isotope separation of Zinc, and admits repeatedly dur
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Some words have more than one meaning. When we say the stranded hikers were exposed to the elements we don't mean they were visible to lanthanum or that silicon was dropping on their heads.
Having said that, the author is an absolute 'dromie for not using substances in the context.
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Empedocles?
Bone dry? (Score:2)
Second, when the Moon was formed there were not even single celled organisms either on Earth or the nascent Moon. Boned animals did not appear till very recently, just 500 million years ago.
see photo, above (Score:2)
Let me understand this surprising discovery. (Score:2)
Well fuck me. I never would have guessed.
How much time and money did they use on this study?
This new learning amazes me (Score:3)
Sir Bedevere: ...and that, my liege, is how we know the Earth to be banana-shaped.
King Arthur : This new learning amazes me, Sir Bedevere. Explain again how sheep's bladders may be employed to prevent earthquakes.
Evaporated and not in the atmosphere? (Score:2)
If it evaporated, wouldn't it have stuck around as part of the atmosphere? Where would it have gone, carried off on fragments doesn't sound so likely?
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Solar particle radiation knocks hydrogen out of the earth's gravitational field. That is, hydrogen atoms achieve escape velocity of 11.186 km/s or more. I guess they mean that the Earth and Moon remained sufficiently hot for sufficiently long.
I thought that Earth was already largely devoid of water since its creation. The creation of Earth amounted to a large mass (one earth mass) falling freely from large distances into the center of the cloud from which the Earth formed, and so hitting the proto-Earth at
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Thank you :) TIL...
Not sure (Score:2)
"Glass From Nuclear Test Site Shows the Moon Was Born Dry "
Empty beer bottles on the moon could mean that, but nuclear glass on earth ...