On this day

In 1980, following a weeklong series of earthquakes and smaller explosions of ash and smoke, the long-dormant Mount St. Helens volcano erupted in Washington state, U.S., hurling ash 15,000 feet into the air and setting off mudslides and avalanches.

Mount St Helens

18/05/1980

An earthquake at 8:32:17 a.m. on Sunday, May 18, 1980, caused the entire weakened north face to slide away, creating the largest landslide ever recorded. This allowed the partly molten, high-pressure gas- and steam-rich rock in the volcano to suddenly explode northwards toward Spirit Lake in a hot mix of lava and pulverized older rock.

Approximately 57 people were killed directly.  Hundreds of square miles were reduced to wasteland, causing over a billion U.S. dollars in damage, thousands of animals were killed, and Mount St. Helens was left with a crater on its north side.

Spirit Lake

Lakes nearest to Mount St. Helens have been partly covered with felled trees for more than thirty years. This photograph was taken in 2012.

For more information visit:-

https://en.wikipedia.org/wiki/1980_eruption_of_Mount_St._Helens

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Today in Science

On this day in history, in 1947, the B.F. Goodrich Company of Akron, Ohio, announced the development of a tubeless tyre.
A technological innovation that would make cars safer and more efficient.
After more than three years of engineering, Goodrich’s tubeless tyre effectively eliminated the inner tube, trapping the pressurised air within the tire walls themselves. By reinforcing those walls, the company claimed, they were able to combine the puncture-sealing features of inner tubes with an improved ease of riding, high resistance to bruising and superior retention of air pressure.  Testing proved successful, and in 1952, Goodrich won patents for the tyre’s various features.  By 1955 tubeless tires became standard equipment on new cars.
Tyres have moved on since with run flat tyres but the basic design has remained the same.
Total Lab Supplies can’t offer tyres but we can offer other safety items.  If you have any requirements get in touch – we can supply safety storage cabinets, spill kits, safety spectacles, signs, labels, gloves and hazardous waste disposal and more
For more information visit:-
https://en.wikipedia.org/wiki/Tubeless_tire
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Separated thermometer columns

Methods For Reuniting Separated Columns In Thermometers

The largest single cause for the failure of precision thermometers in the lab is the separation of mercury columns. This can occur in transit or in the lab. The life of the thermometer can be greatly extended if the following procedures are employed. Other methods may damage the thermometer.

Cooling Method

With the thermometer in an upright position, gradually immerse only the bulb in a solution of solid CO2 (Dry Ice) and alcohol so that the mercury column retreats slowly into the bulb. Do not cool the stem or mercury column. Keep the bulb in the solution until the main column and the separated portion retreat into the bulb. Remove and swing thermometer in a short arc, forcing all the mercury into the bulb.

Most mercury thermometers can be reunited using this method regardless of range (with the exception of deep immersion thermometers) provided only the bulb is immersed in the CO2 and alcohol solution.

Caution: Do not touch the bulb until it has warmed sufficiently for the mercury to emerge from the bulb into the capillary. Never subject the stem or mercury column to the CO2 solution as it will freeze the mercury column in the capillary and may cause the bulb to fracture.

Heating Method

This method applies to thermometers with a maximum range of 260°C (500°F) equipped with expansion chambers sufficiently large to accommodate the separations plus a portion of the main column. Immerse as much of the bulb and stem as possible in a large beaker containing a liquid whose flash point is well above the highest indication of the thermometer being reunited. Heat the beaker, stirring the liquid with the thermometer, until the separation and a portion of the main column enter the chamber. Tap the thermometer in the palm of gloved hand reuniting the column. Allow to cool slowly.

Caution:

  1. Never use an open flame on the bulb.
  1. Never fill the expansion chamber more than two-thirds full.
  1. Make certain the flash point of the liquid is well above the highest temperature indicated on the thermometer.
  1. Thermometers whose ranges exceed 260°C (500°F) cannot be reunited using heat without damaging the instrument.

Reuniting Organic-Filled Columns

Separated columns in organic-filled (spirit) thermometers require a somewhat different technique in order to be reunited. The simplest and safest method is to force the liquid down the capillary by using a centrifuge, if one is available, with a cup deep enough to ensure that the centrifugal force is below the liquid column. Carefully insert the thermometer, bulb down, in the centrifuge. Have some cotton wadding at the bottom of the cup to prevent any damage to the bulb. Turn on the centrifuge and in just a few seconds all the liquid will be forced past the separation. If the cup is not deep enough and all the centrifugal force is not below the column, the column will split, forcing part of the liquid down. The remainder will be forced up, filling the expansion chamber.

If a centrifuge is not available, the column can be reunited by getting the liquid to run down. This can be accomplished by holding the thermometer in an upright position and gingerly tapping the stem above the separation against the palm of your hand. As you gently tap the thermometer, observe the liquid above the separation until it breaks away from the wall of the capillary and runs down to join the main column.

Remember, mercury in glass thermometers are no longer available.  Contact us for equivalent thermometers which can be supplied as they are or with UKAS calibrations.

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The chemistry behind why you shouldn’t eat laundry pods

Laundry pods have featured in the news this week after cases of people eating them in what’s being referred to as the ‘Tide Pod Challenge’. In case you didn’t already realise that this is a pretty terrible idea, this graphic looks at the chemical reasons why you really don’t want them anywhere near your mouth

The Chemistry of Laundry pods



Eating laundry pods is particularly risky since the detergents are at a higher concentration than in liquid detergents. They are highly alkaline; just as highly acidic substances can cause burns, so too can very alkaline ones. If you eat a laundry pod, you run the risk of burns to your throat and stomach from the high concentration detergent they contain. As they pop in your mouth, they can also be accidentally inhaled – definitely not good for your airway and lungs either.

In addition, eating them can also cause breathing problems. Why exactly this is is currently unclear. It seems that in some laundry pod formulations, a sedative effect is seen when they are ingested. This can lead to drowsiness and breathing difficulties. It’s been speculated that a solvent used in the pods, propylene glycol, might contribute. Alternatively, it might be an unknown effect of certain ethoxylated alcohols.


Laundry pods like this also contain a bitter substance to deter children from putting them in their mouths.  For more information visit the full article at the excellent Compound Interest


http://ift.tt/2GiQClE


For all your chemical needs contact us on 01744 455000


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Happy New Year!

When is it too late to say Happy New Year?  When you first meet someone after the holiday break?  After the first week?  Second week?


Anyway, Total Lab Supplies wishes you a Happy New Year and all the best for 2018.


If you require a catalogue then please contact us on 01744 455000 or e-mail sales@totallabsupplies.co.uk


We can supply a wide range of branded chemicals from Fisher, Acros, Alfa, Honeywell, Fluka and more.  From solvents and acids to more specialist chemicals.  All at competitive prices.  Buying these chemicals you can be assured of quality products.


Please don’t hesitate to get in touch with us and we’ll help you find what you’re looking for.

 

 

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On this day in science history: the first U.S. patent for a liquid soap was issued

In 1865, the first U.S. patent for a liquid soap was issued to William Sheppard of New York City (No. 49,561). The patent described his “discovery that by the addition of comparatively small quantities of common soap to a large quantity of spirits of ammonia or hartshorn is thickened to the consistency of molasses, and a liquid soap is obtained of superior detergent qualities.” The proportions given were to dissolve one pound of common soap in water or steam, and then add 100-lbs of ammonia such that the liquid thickens to the consistency of molasses. The product was expected to be useful for both domestic and manufacturing purposes. (Hartshorn is an ancient name for an aqueous solution of ammonia).
 
Decorative soaps, by Phanton at English Wikipedia (Transferred from en.wikipedia to Commons.) [Public domain], via Wikimedia Commons
So, how does soap clean?
 
Action of soap
 
When used for cleaning, soap allows insoluble particles to become soluble in water, so they can then be rinsed away. For example: oil/fat is insoluble in water, but when a couple of drops of dish soap are added to the mixture, the oil/fat dissolves in the water. The insoluble oil/fat molecules become associated inside micelles, tiny spheres formed from soap molecules with polar hydrophilic (water-attracting) groups on the outside and encasing a lipophilic (fat-attracting) pocket, which shields the oil/fat molecules from the water making it soluble. Anything that is soluble will be washed away with the water.
 
Effect of the alkali
 
The type of alkali metal used determines the kind of soap product. Sodium soaps, prepared from sodium hydroxide, are firm, whereas potassium soaps, derived from potassium hydroxide, are softer or often liquid. Historically, potassium hydroxide was extracted from the ashes of bracken or other plants. Lithium soaps also tend to be hard—these are used exclusively in greases.
 
Effects of fats
 
Soaps are derivatives of fatty acids. Traditionally they have been made from triglycerides (oils and fats). Triglyceride is the chemical name for the triesters of fatty acids and glycerin. Tallow, i.e., rendered beef fat, is the most available triglyceride from animals. Its saponified product is called sodium tallowate. Typical vegetable oils used in soap making are palm oil, coconut oil, olive oil, and laurel oil. Each species offers quite different fatty acid content and hence, results in soaps of distinct feel. The seed oils give softer but milder soaps. Soap made from pure olive oil is sometimes called Castile soap or Marseille soap, and is reputed for being extra mild. The term “Castile” is also sometimes applied to soaps from a mixture of oils, but a high percentage of
olive oil.
 
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Lunar dynamo’s lifetime extended by at least 1 billion years

New evidence from ancient lunar rocks suggests that an active dynamo once churned within the molten metallic core of the moon, generating a magnetic field that lasted at least 1 billion years longer than previously thought. Dynamos are natural generators of magnetic fields around terrestrial bodies, and are powered by the churning of conducting fluids within many stars and planets. In a paper published today in Science Advances, researchers from MIT and Rutgers University report that a lunar rock collected by NASA’s Apollo 15 mission exhibits signs that it formed 1 to 2.5 billion years ago in the presence of a relatively weak magnetic field of about 5 microtesla. That’s around 10 times weaker than Earth’s current magnetic field but still 1,000 times larger than fields in interplanetary space today.
 
Full moon as seen from Earth’s Northern Hemisphere, by Gregory H. Revera (Own work) [CC BY-SA 3.0 (http://ift.tt/HKkdTz) or GFDL (http://ift.tt/KbUOlc)], via Wikimedia Commons
Several years ago, the same researchers identified 4-billion-year-old lunar rocks that formed under a much stronger field of about 100 microtesla, and they determined that the strength of this field dropped off precipitously around 3 billion years ago. At the time, the researchers were unsure whether the moon’s dynamo – the related magnetic field – died out shortly thereafter or lingered in a weakened state before dissipating completely.
 
The results reported today support the latter scenario: After the moon’s magnetic field dwindled, it nonetheless persisted for at least another billion years, existing for a total of at least 2 billion years.
 
Study co-author Benjamin Weiss, professor of planetary sciences in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS), says this new extended lifetime helps to pinpoint the phenomena that powered the moon’s dynamo. Specifically, the results raise the possibility of two different mechanisms – one that may have driven an earlier, much stronger dynamo, and a second that kept the moon’s core simmering at a much slower boil toward the end of its lifetime.
 
“The concept of a planetary magnetic field produced by moving liquid metal is an idea that is really only a few decades old,” Weiss says. “What powers this motion on Earth and other bodies, particularly on the moon, is not well-understood. We can figure this out by knowing the lifetime of the lunar dynamo.”
 
Weiss’ co-authors are lead author Sonia Tikoo, a former MIT graduate student who is now an assistant professor at Rutgers; David Shuster of the University of California at Berkeley; Clément Suavet and Huapei Wang of EAPS; and Timothy Grove, the R.R. Schrock Professor of Geology and associate head of EAPS.
 
Since NASA’s Apollo astronauts brought back samples from the lunar surface, scientists have found some of these rocks to be accurate “recorders” of the moon’s ancient magnetic field. Such rocks contain thousands of tiny grains that, like compass needles, aligned in the direction of ancient fields when the rocks crystallized eons ago. Such grains can give scientists a measure of the moon’s ancient field strength.
 
Until recently, Weiss and others had been unable to find samples much younger than 3.2 billion years old that could accurately record magnetic fields. As a result, they had only been able to gauge the strength of the moon’s magnetic field between 3.2 and 4.2 billion years ago.
 
“The problem is, there are very few lunar rocks that are younger than about 3 billion years old, because right around then, the moon cooled off, volcanism largely ceased and, along with it, formation of new igneous rocks on the lunar surface,” Weiss explains. “So there were no young samples we could measure to see if there was a field after 3 billion years.”
 
There is, however, a small class of rocks brought back from the Apollo missions that formed not from ancient lunar eruptions but from asteroid impacts later in the moon’s history. These rocks melted from the heat of such impacts and recrystallized in orientations determined by the moon’s magnetic field.
 
Weiss and his colleagues analyzed one such rock, known as Apollo 15 sample 15498, which was originally collected on Aug. 1, 1971, from the southern rim of the moon’s Dune Crater. The sample is a mix of minerals and rock fragments, welded together by a glassy matrix, the grains of which preserve records of the moon’s magnetic field at the time the rock was assembled.
 
“We found that this glassy material that welds things together has excellent magnetic recording properties,” Weiss says.
 
The team determined that the rock sample was about 1 to 2.5 billion years old – much younger than the samples they previously analyzed. They developed a technique to decipher the ancient magnetic field recorded in the rock’s glassy matrix by first measuring the rock’s natural magnetic properties using a very sensitive magnetometer.
 
They then exposed the rock to a known magnetic field in the lab, and heated the rock to close to the extreme temperatures in which it originally formed. They measured how the rock’s magnetization changed as they increased the surrounding temperature.
 
“You see how magnetized it gets from getting heated in that known magnetic field, then you compare that field to the natural magnetic field you measured beforehand, and from that you can figure out what the ancient field strength was,” Weiss explains.
 
The researchers did have to make one significant adjustment to the experiment to better simulate the original lunar environment, and in particular, its atmosphere. While the Earth’s atmosphere contains around 20 percent oxygen, the moon has only imperceptible traces of the gas. In collaboration with Grove, Suavet built a customized, oxygen-deprived oven in which to heat the rocks, preventing them from rusting while at the same time simulating the oxygen-free environment in which the rocks were originally magnetized.
 
“In this way, we finally have gotten an accurate measurement of the lunar field,” Weiss says.
 
From their experiments, the researchers determined that, around 1 to 2.5 billion years ago, the moon harbored a relatively weak magnetic field, with a strength of about 5 microtesla – two orders of magnitude weaker than the moon’s field around 3 to 4 billion years ago. Such a dramatic dip suggests to Weiss and his colleagues that the moon’s dynamo may have been driven by two distinct mechanisms.
 
Scientists have proposed that the moon’s dynamo may have been powered by the Earth’s gravitational pull. Early in its history, the moon orbited much closer to the Earth, and the Earth’s gravity, in such close proximity, may have been strong enough to pull on and rotate the rocky exterior of the moon. The moon’s liquid center may have been dragged along with the moon’s outer shell, generating a very strong magnetic field in the process.
 
It’s thought that the moon may have moved sufficiently far away from the Earth by about 3 billion years ago, such that the power available for the dynamo by this mechanism became insufficient. This happens to be right around the time the moon’s magnetic field strength dropped. A different mechanism may have then kicked in to sustain this weakened field. As the moon moved away from the Earth, its core likely sustained a low boil via a slow process of cooling over at least 1 billion years.
 
“As the moon cools, its core acts like a lava lamp – low-density stuff rises because it’s hot or because its composition is different from that of the surrounding fluid,” Weiss says. “That’s how we think the Earth’s dynamo works, and that’s what we suggest the late lunar dynamo was doing as well.”
 
The researchers are planning to analyze even younger lunar rocks to determine when the dynamo died off completely.
 
“Today the moon’s field is essentially zero,” Weiss says. “And we now know it turned off somewhere between the formation of this rock and today.”
 
This research was supported, in part, by NASA.
 
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Protein-rich diet may help soothe inflamed gut

Immune cells patrol the gut to ensure that harmful microbes hidden in the food we eat don’t sneak into the body. Cells that are capable of triggering inflammation are balanced by cells that promote tolerance, protecting the body without damaging sensitive tissues. When the balance tilts too far toward inflammation, inflammatory bowel disease can result.
 
Now, researchers at Washington University School of Medicine in St. Louis have found that a kind of tolerance-promoting immune cell appears in mice that carry a specific bacterium in their guts. Further, the bacterium needs tryptophan – one of the building blocks of proteins – to trigger the cells’ appearance.
 
“We established a link between one bacterial species – Lactobacillus reuteri – that is a normal part of the gut microbiome, and the development of a population of cells that promote tolerance,” said Marco Colonna, MD, the Robert Rock Belliveau MD Professor of Pathology and the study’s senior author. “The more tryptophan the mice had in their diet, the more of these immune cells they had.”
 
If such findings hold true for people, it would suggest that the combination of L. reuteri and a tryptophan-rich diet may foster a more tolerant, less inflammatory gut environment, which could mean relief for the million or more Americans living with the abdominal pain and diarrhea of inflammatory bowel disease.
 
A representation of the 3D structure of the protein myoglobin showing turquoise α-helices. By AzaToth (self made based on PDB entry) [Public domain], via Wikimedia Commons
Postdoctoral researcher Luisa Cervantes-Barragan, PhD, was studying a kind of immune cell that promotes tolerance when she discovered that one group of study mice had such cells, while a second group of study mice that were the same strain of mice but were housed far apart from the first group did not have such cells.
 
The mice were genetically identical but had been born and raised separately, indicating that an environmental factor influenced whether the immune cells developed.
 
She suspected the difference had to do with the mice’s gut microbiomes – the community of bacteria, viruses and fungi that normally live within the gastrointestinal tract.
 
Cervantes-Barragan collaborated with Chyi-Song Hsieh, MD, PhD, the Alan A. and Edith L. Wolff Distinguished Professor of Medicine, to sequence DNA from the intestines of the two groups of mice. They found six bacterial species present in the mice with the immune cells but absent from the mice without them.
 
With the help of Jeffrey I. Gordon, MD, the Dr. Robert J. Glaser Distinguished University Professor, the researchers turned to mice that had lived under sterile conditions since birth to identify which of the six species was involved in inducing the immune cells. Such mice lack a gut microbiome and do not develop this kind of immune cell. When L. reuteri was introduced to the germ-free mice, the immune cells arose.
 
To understand how the bacteria affected the immune system, the researchers grew L. reuteri in liquid and then transferred small amounts of the liquid – without bacteria – to immature immune cells isolated from mice. The immune cells developed into the tolerance-promoting cells. When the active component was purified from the liquid, it turned out to be a byproduct of tryptophan metabolism known as indole-3-lactic acid.
 
Tryptophan – commonly associated with turkey – is a normal part of the mouse and the human diet. Protein-rich foods contain appreciable amounts: nuts, eggs, seeds, beans, poultry, yogurt, cheese, even chocolate.
 
When the researchers doubled the amount of tryptophan in the mice’s feed, the number of such cells rose by about 50 percent. When tryptophan levels were halved, the number of cells dropped by half.
 
People have the same tolerance-promoting cells as mice, and most of us shelter L. reuteri in our gastrointestinal tracts. It is not known whether tryptophan byproducts from L. reuteri induce the cells to develop in people as they do in mice, but defects in genes related to tryptophan have been found in people with inflammatory bowel disease.
 
“The development of these cells is probably something we want to encourage since these cells control inflammation on the inner surface of the intestines,” Cervantes-Barragan said. “Potentially, high levels of tryptophan in the presence of L. reuteri may induce expansion of this population.”
 
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On this day in science history: oxygen was identified

In 1774, Joseph Priestley, British Presbyterian minister and chemist, identified a gas which he called “dephlogisticated air” – later known as oxygen. Priestley found that mercury heated in air became coated with “red rust of mercury,” which, when heated separately, was converted back to mercury with “air” given off. Studying this “air” given off, he observed that candles burned very brightly in it. Also, a mouse in a sealed vessel with it could breathe it much longer than ordinary air. A strong believer in the phlogiston theory, Priestley considered it to be “air from which the phlogiston had been removed.” Further experiments convinced him that ordinary air is one fifth dephlogisticated air, the rest considered by him to be phlogiston.
 
Joseph Priestley, by Charles Turner [Public domain], via Wikimedia Commons
However, oxygen was in fact first discovered earlier, by Swedish pharmacist Carl Wilhelm Scheele. He had produced oxygen gas by heating mercuric oxide and various nitrates in 1771–2. Scheele called the gas “fire air” because it was the only known supporter of combustion, and wrote an account of this discovery in a manuscript he titled Treatise on Air and Fire, which he sent to his publisher in 1775. That document was published in 1777. 
 
Because Priestly published his findings first, he is usually given priority in the discovery.
 
The French chemist Antoine Laurent Lavoisier later claimed to have discovered the new substance independently. Priestley visited Lavoisier in October 1774 and told him about his experiment and how he liberated the new gas. Scheele also posted a letter to Lavoisier on September 30, 1774 that described his discovery of the previously unknown substance, but Lavoisier never acknowledged receiving it (a copy of the letter was found in Scheele’s belongings after his death). Long before this, one of the first known experiments on the relationship between combustion and air was conducted by the 2nd century BCE Greek writer on mechanics, Philo of Byzantium. In his work Pneumatica, Philo observed that inverting a vessel over a burning candle and surrounding the vessel’s neck with water resulted in some water rising into the neck. Philo incorrectly surmised that parts of the air in the vessel were converted into the classical element fire and thus were able to escape through pores in the glass. Many centuries later Leonardo da Vinci built on Philo’s work by observing that a portion of air is consumed during combustion and respiration.
 
In the late 17th century, Robert Boyle proved that air is necessary for combustion. English chemist John Mayow (1641–1679) refined this work by showing that fire requires only a part of air that he called spiritus nitroaereus. In one experiment, he found that placing either a mouse or a lit candle in a closed container over water caused the water to rise and replace one-fourteenth of the air’s volume before extinguishing the subjects. From this he surmised that nitroaereus is consumed in both respiration and combustion.
 
Mayow observed that antimony increased in weight when heated, and inferred that the nitroaereus must have combined with it. He also thought that the lungs separate nitroaereus from air and pass it into the blood and that animal heat and muscle movement result from the reaction of nitroaereus with certain substances in the body. Accounts of these and other experiments and ideas were published in 1668 in his work Tractatus duo in the tract “De respiratione”.
 
Robert Hooke, Ole Borch, Mikhail Lomonosov, and Pierre Bayen all produced oxygen in experiments in the 17th and the 18th century but none of them recognized it as a chemical element. This may have been in part due to the prevalence of the philosophy of combustion and corrosion called the phlogiston theory, which was then the favored explanation of those processes.
 
Established in 1667 by the German alchemist J. J. Becher, and modified by the chemist Georg Ernst Stahl by 1731, phlogiston theory stated that all combustible materials were made of two parts. One part, called phlogiston, was given off when the substance containing it was burned, while the dephlogisticated part was thought to be its true form, or calx.
 
Highly combustible materials that leave little residue, such as wood or coal, were thought to be made mostly of phlogiston; non-combustible substances that corrode, such as iron, contained very little. Air did not play a role in phlogiston theory, nor were any initial quantitative experiments conducted to test the idea; instead, it was based on observations of what happens when something burns, that most common objects appear to become lighter and seem to lose something in the process. The fact that a substance like wood gains overall weight in burning was hidden by the buoyancy of the gaseous combustion products.
 
This theory, while it was on the right track, was unfortunately set up backwards. Rather than combustion or corrosion occurring as a result of the decomposition of phlogiston compounds into their base elements with the phlogiston being lost to the air, it is in fact the result of oxygen from the air combining with the base elements to produce oxides. Indeed, one of the first clues that the phlogiston theory was incorrect was that metals gain weight in rusting (when they were supposedly losing phlogiston).
 
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Moon has a water-rich interior

A new study of satellite data finds that numerous volcanic deposits distributed across the surface of the Moon contain unusually high amounts of trapped water compared with surrounding terrains. The finding of water in these ancient deposits, which are believed to consist of glass beads formed by the explosive eruption of magma coming from the deep lunar interior, bolsters the idea that the lunar mantle is surprisingly water-rich.
 
Scientists had assumed for years that the interior of the Moon had been largely depleted of water and other volatile compounds. That began to change in 2008, when a research team including Brown University geologist Alberto Saal detected trace amounts of water in some of the volcanic glass beads brought back to Earth from the Apollo 15 and 17 missions to the Moon. In 2011, further study of tiny crystalline formations within those beads revealed that they actually contain similar amounts of water as some basalts on Earth. That suggests that the Moon’s mantle – parts of it, at least – contain as much water as Earth’s.
 
“The key question is whether those Apollo samples represent the bulk conditions of the lunar interior or instead represent unusual or perhaps anomalous water-rich regions within an otherwise ‘dry’ mantle,” said Ralph Milliken, lead author of the new research and an associate professor in Brown’s Department of Earth, Environmental and Planetary Sciences. “By looking at the orbital data, we can examine the large pyroclastic deposits on the Moon that were never sampled by the Apollo or Luna missions. The fact that nearly all of them exhibit signatures of water suggests that the Apollo samples are not anomalous, so it may be that the bulk interior of the Moon is wet.”
 
Full Moon photograph taken 10-22-2010 from Madison, Alabama, USA. By Gregory H. Revera (Own work) [CC BY-SA 3.0 (http://ift.tt/HKkdTz) or GFDL (http://ift.tt/KbUOlc)], via Wikimedia Commons
The research, which Milliken co-authored with Shuai Li, a postdoctoral researcher at the University of Hawaii and a recent Brown Ph.D. graduate, is published in Nature Geoscience.
 
Detecting the water content of lunar volcanic deposits using orbital instruments is no easy task. Scientists use orbital spectrometers to measure the light that bounces off a planetary surface. By looking at which wavelengths of light are absorbed or reflected by the surface, scientists can get an idea of which minerals and other compounds are present.
 
The problem is that the lunar surface heats up over the course of a day, especially at the latitudes where these pyroclastic deposits are located. That means that in addition to the light reflected from the surface, the spectrometer also ends up measuring heat.
 
“That thermally emitted radiation happens at the same wavelengths that we need to use to look for water,” Milliken said. “So in order to say with any confidence that water is present, we first need to account for and remove the thermally emitted component.”
 
To do that, Li and Milliken used laboratory-based measurements of samples returned from the Apollo missions, combined with a detailed temperature profile of the areas of interest on the Moon’s surface. Using the new thermal correction, the researchers looked at data from the Moon Mineralogy Mapper, an imaging spectrometer that flew aboard India’s Chandrayaan-1 lunar orbiter.
 
The researchers found evidence of water in nearly all of the large pyroclastic deposits that had been previously mapped across the Moon’s surface, including deposits near the Apollo 15 and 17 landing sites where the water-bearing glass bead samples were collected.
 
“The distribution of these water-rich deposits is the key thing,” Milliken said. “They’re spread across the surface, which tells us that the water found in the Apollo samples isn’t a one-off. Lunar pyroclastics seem to be universally water-rich, which suggests the same may be true of the mantle.”
 
The idea that the interior of the Moon is water-rich raises interesting questions about the Moon’s formation. Scientists think the Moon formed from debris left behind after an object about the size of Mars slammed into the Earth very early in solar system history. One of the reasons scientists had assumed the Moon’s interior should be dry is that it seems unlikely that any of the hydrogen needed to form water could have survived the heat of that impact.
 
“The growing evidence for water inside the Moon suggest that water did somehow survive, or that it was brought in shortly after the impact by asteroids or comets before the Moon had completely solidified,” Li said. “The exact origin of water in the lunar interior is still a big question.”
 
In addition to shedding light on the water story in the early solar system, the research could also have implications for future lunar exploration. The volcanic beads don’t contain a lot of water – about .05 percent by weight, the researchers say – but the deposits are large, and the water could potentially be extracted.
 
“Other studies have suggested the presence of water ice in shadowed regions at the lunar poles, but the pyroclastic deposits are at locations that may be easier to access,” Li said. “Anything that helps save future lunar explorers from having to bring lots of water from home is a big step forward, and our results suggest a new alternative.”
 
The research was funded by the NASA Lunar Advanced Science and Exploration Research Program (NNX12AO63G).
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