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Glass From Nuclear Test Site Shows the Moon Was Born Dry (newscientist.com)
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.
I always assumed it had a placenta.
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?
How is this not extremely obvious? Of course volatile stuff boils off from the Moon.
Did part of the mantle get blown off to make the moon or it all crust?
Nuclear explosions on the moon... Inherit the Stars explains it well. :)
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 environment of the original surface.
If we were to judge the entirety of the human body by what we can scrape off the surface with small weak tools unable to break the surface you're not going to see much. Lets poke a real hole in the moon or mars and see whats inside.
~ People that think they are better than anyone else for any reason are the cause of all the strife in the world.
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 . . .
redneck geek
Good comment; agree.
But while we're picking nits....
https://en.wikipedia.org/wiki/...
Ayup - I always assumed that one cannot have hot molten rock and liquid water in the same place at the same time, so the earth and other planets must have accumulated their water and ice from the surrounding clouds of gas and comets at a later stage.
.. just so happened to just release a very interesting video on this topic.
https://www.youtube.com/watch?v=hbXDLKFkjm0
;)
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.
redneck geek
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 facts have been around for over 100 years.
You would have to have ice in permanent shadow at the bottom of a polar crater to get water. But, on a side note, we already sent impactors to the most likely place where water could theoretically exist and did not find any.
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?
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.
You were already shown to be wrong ages ago when they found massive amounts of water trapped in crystalized rocks deep underground.
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.
Dang. O_o
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 is basically only about isotope separation of Zinc, and admits repeatedly during its text that other "studies of volatile compounds, such as water or OH in lunar glasses, suggest that the Moon may have volatile element abundances approaching Earth’s upper mantle composition".
tl;dr: This paper looked at what happens to Zinc isotopes at the center of a nuclear explosion. Everything else is conjecture, which they openly admit is contradicted by other studies. TFA in New Scientist omits the contradictory evidence and builds conjectures on top of those conjectures, until what they say has almost nothing to do with the actual article.
Enjoy life! This is not a dress rehearsal.
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.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
true. It's not like water evaporated from the moon "while cooling". How would the water beat the gravity of the moon? It must have escaped before the moon was formed.
Time to take time out from bashing Slashdot and its paid staff (yes, these editors actually get paid, I hear) to remind ourselves of some of its goodness. In this case, it's that fact that Slashdot thankfully still doesn't include images with summaries - that makes the content much easier to scan.
The thousands of degrees of heat created by the impact, "boiled off" any water?
Well fuck me. I never would have guessed.
How much time and money did they use on this study?
Why is it so hard to only have politicians for a few years, then have them go away?
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.
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 thick white stuff, not the thin clear stuff. Insert inappropriate joke here.) And (again, at least in the USA) you can order benzyl alcohol in bulk online from various suppliers, and creamy baby oil from Amazon, for very cheap.
So, buy your ingredients, mix them in the proper proportions, apply for ten minutes then wash hair thoroughly. 7-10 days later do the same thing. The benzyl alcohol won't kill nits (eggs) but it will kill live lice. And the life cycle of lice is such that a 7-10 days allows the remaining viable eggs to hatch, but isn't long enough for the newly hatched lice to reach breeding age.
Now, here's the fun part. Because this stuff is cheap, you can mix up a bunch, put it in disposable plastic containers, and quietly distribute it to friends/family/classmates. Some people are really twitchy about their kid having lice (they're just bugs, people, it happens) so providing them with a free, simple solution may get them to act when the otherwise would be too embarrassed to otherwise do anything about it.
Source: my daughters' cousins kept passing lice to my kids, and we couldn't get rid of the stupid things until we passed this stuff around to pretty much our entire extended family.
Wait, what did this have to do with the origins of the moon? :)
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?
Twinstiq, game news
They should shoot some nukes on the moon and see how the Zinc evaporates as the massive tidal waves obliterate Earth.
Is this how to make awesome crystals at home?
CLI paste? paste.pr0.tips!
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.
"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 ...
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 smaller relative to the parent body than Luna is to Earth. Luna is very likely a fair-sized chunk of Theia, mixed in with smaller chunks of Earth, and coated in both Earth dust and Theia dust.
Really, we're not going to know until we drill and take cores, plus do seismic imaging. Solving the n-body problem on that scale requires simplifying assumptions (in either your explanation or mine) so vast that it just reduces the whole thing to guesswork. If we really want to know, we're going to have to go and look.