Tag Archives: helium

Magnetic field readings point to the structure of Saturn’s interior

Researchers at the Johns Hopkins University have completed a new model of Saturn’s interior, which hints at a thick layer of helium rain that modulates the gas giant’s magnetic field.

Saturn’s interior with stably stratified Helium Insoluble Layer (HIL). Image credits Yi Zheng (HEMI/MICA Extreme Arts Program) / Johns Hopkins University.

The so-called ‘gas giants’ are notoriously hard to peer into, and they remain some of the most mysterious planets out there. Given the extreme environments they represent, it’s likely going to be a while before this changes, and an even longer while before any astronauts can actually go see for themselves.

That doesn’t mean we can’t draw some conclusions based on what we do know, however. And a team from Johns Hopkins University did just that, creating a new digital model looking into Saturn’s interior. This model hints at a temperature difference in the helium rain layer between the planet’s equator (where it is hotter) and the poles (where it gets colder).

Hot waist

“By studying how Saturn formed and how it evolved over time, we can learn a lot about the formation of other planets similar to Saturn within our own solar system, as well as beyond it,” said co-author Sabine Stanley, a Johns Hopkins planetary physicist.

“One thing we discovered was how sensitive the model was to very specific things like temperature,” she adds. “And that means we have a really interesting probe of Saturn’s deep interior as far as 20,000 kilometers down. It’s a kind of X-ray vision.”

Saturn is unique among the other gas giants in that its magnetic field is almost perfectly symmetrical around its axis. Since magnetic fields are generated by structures inside a planet’s body, this tidbit could help us glean some information about Saturn’s interior layout.

Using data recorded by NASA’s Cassini mission, researchers at Johns Hopkins University created detailed computer simulations using software typically employed for weather and climate simulations. The models indicate that there is a heat gradient in Saturn’s interior, with higher temperatures towards the equator. Overall, this could point to the existence of a layer of liquid helium around the planet’s core.

The magnetic field of Saturn seen at the surface. Image credits Ankit Barik / Johns Hopkins University.

This structure creates a dynamo-like mechanism, which goes on to produce the striking magnetic field recorded around Saturn. On Earth, the planet’s iron core and molten metal mantle play the role of dynamo. It was expected that gas giants rely on a different structure to create their magnetic field, given their different chemical composition and extreme mass, but this is the first study to actually pinpoint one candidate structure for this role in gas giants.

Apart from this, the simulations also suggest that a certain level of non-axisymmetry could be present near Saturn’s north and south poles.

“Even though the observations we have from Saturn look perfectly symmetrical, in our computer simulations we can fully interrogate the field,” said Stanley.

Naturally, until we can put a person on Saturn to check, we can’t confirm these findings. Until then, models will have to suffice.

The paper “Recipe for a Saturn‐Like Dynamo” has been published in the journal AGU Advances.

What are stars made of?

We’re all made of star dust — an often-quoted phrase referring to the fact that nearly all the elements in the human body were forged in a star. But what are stars, themselves, made of?

Actually, stars are made of the same chemical elements as planet Earth, though not nearly in the same proportions. The vast majority of stars are made almost entirely of hydrogen (about 90%) and helium (about 10%) — elements that are relatively rare on our planet, and the lightest on the periodic table  — while all the other elements represent just 0.1%.

Among other elements, oxygen usually dominates, followed by carbon, neon, and nitrogen, with iron being the most common metal element. Still, there is only one atom of oxygen in the Sun for every 1200 hydrogen atoms and only one of iron for every 32 oxygen atoms.

It makes sense that hydrogen is the dominant element of the sun and other stars. In order to burn bright for billions of years, stars convert hydrogen into helium through a constant nuclear reaction similar to a hydrogen bomb. So, in a sense, the sun is in a state of constant nuclear explosion, and only appears as a solid sphere because it’s held together by its own massive gravity.

What’s more, as we’ll see, the composition and chemical makeup of stars can vary considerably depending on their states of aging or upon where they are in the galaxy.

Also, elements other than hydrogen or helium can be forged by stars, but only towards the end of their life cycle. Typically, in a star such as the Sun, the heavier elements were seeded by stars that existed before it. Some stars go out with a bang, producing a supernova — a powerful and luminous explosion — during their last evolutionary stages, which ejects heavy elements into space. So new stars can incorporate this material. Due to the laws of physics, the universe recycles everything.

Not all stars glitter the same, nor are they made of the same stuff

Credit: Wikimedia Commons.

All stars are amazing in their own way, but some shine more brightly than others. Hot stars appear white or blue when observed from Earth, whereas cooler stars appear in orange or red hues. Astronomers plot a star’s luminosity and temperature onto a graph called the Hertzsprung-Russell diagram, which is useful to classify stars.

Although there are many types of stars, the most common are main sequence stars — about 90% of all known stars, including the Sun, are in this class.

Below main sequence stars are white dwarfs, the stellar core remnant after a star has exhausted all its fuel. These ancient stars are incredibly dense. A teaspoonful of their matter would weigh as much on Earth as an elephant.

Such densities are possible because white dwarf material is not composed of atoms joined by chemical bonds, but rather consists of a plasma of unbound nuclei and electrons. For this reason, nuclei can be placed closer than normally allowed by electron orbitals in normal matter.

Because white dwarfs are the remnant cores of normal stars, they are primarily made of the “waste” products of the nuclear fusion reactions that they used to support.  These “waste” products are primarily carbon and oxygen, with traces of other elements.  But that’s not to say there isn’t helium and hydrogen left. The outer part of a white dwarf contains the two elements.  And due to the tremendous gravitational force associated with these dense stars, these elements are stratified with the heaviest elements residing at the deepest depths in the star. 

Above main sequence stars are ‘giants’ and ‘supergiants’. Before stars reach the very end of their evolution — when they turn into dwarfs or explode into supernovae — they condense and compact, heating up further as the last of their hydrogen is burned. This causes the star’s outer layers to expand outward. At this stage, the star becomes a large red giant.

According to an old study published in the 1985 edition of the Astrophysical Journal, red giants are mainly made of helium and hydrogen, along with carbon, oxygen, nitrogen, and iron. Astrophysicists also recorded the presence of heavy s-process elements such as strontium, yttrium, zirconium, barium, and neodymium.

Credit: Wikimedia Commons.

Supergiants are among the most massive and luminous stars in the universe. Stars that are ten times bigger than the sun (or larger) will turn into supergiants when they run out of fuel. They are similar to red giants in composition except that they are, you guessed it, much larger.

The Sun is expected to turn into a red giant once it exhausts its fuel. Luckily, that won’t happen for another five billion years.

Helium exoplanet inflates like a balloon

It’s the first time anything like this has ever been observed and could teach us a lot about the hottest exoplanets ever discovered.

Hat-P-11b (right) is a gas giant, comparable in size to Neptune (left).

The planet HAT-P-11b, also called Kepler-3b, was discovered in 2009 with the Kepler telescope. Like most exoplanets, it was discovered through the transit method — we didn’t see it directly, but as the planet passes in front of its star, it creates a slight dim point, and from that, several of its characteristics can be calculated. Because planets themselves don’t generate light, it is typically much easier to detect them with the aid of their star.

For instance, in September 2014, NASA reported that HAT-P-11b is the first Neptune-sized exoplanet known to have a relatively cloud-free atmosphere. But other than that, nothing stood out about this planet — until now. An international team of researchers, led by Jessica Spake and Dr. David Sing from the University of Exeter, has found evidence that inert gas is escaping from the atmosphere of the exoplanet.

Although helium is rather rare here on Earth, it’s essentially ubiquitous in space — second only after hydrogen. However, although it is so common, it has only been recently observed in the atmosphere of a gaseous giant. Helium was long-predicted to be one of the most common gases on giant exoplanets, but observations have proven quite challenging. Helium was only observed on an exoplanet once before, in a study also led by Jessica Spake that used the Hubble telescope. Researchers also found that the helium has swollen up the planet’s atmosphere, much like a helium balloon inflates. Spake explains:

“This is a really exciting discovery, particularly as helium was only detected in exoplanet atmospheres for the first time earlier this year. The observations show helium being blasted away from the planet by radiation from its host star. Hopefully we can use this new study to learn what types of planets have large envelopes of hydrogen and helium, and how long they can hold the gases in their atmospheres.”

Artist’s impression of the exoplanet HAT-P-11b with its extended helium atmosphere blown away by its star, an orange dwarf star that is smaller but more active, than the Sun. Image credits: Denis Bajram.

Their observations were complemented and confirmed by numerical simulations, which allowed researchers to track the trajectory of these helium atoms. Vincent Bourrier, the co-author who carried these simulations, says that Hat-P-11b must be quite a hellish place.

“Helium is blown away from the day side of the planet to its night side at over 10,000 km/h,” Bourrier explains. “Because it is such a light gas, it escapes easily from the attraction of the planet and forms an extended cloud all around it.” This gives HAT-P-11b the shape of a helium-inflated balloon.

This would make it one of the hottest exoplanets ever discovered, and it also shows that this type of observation, once thought to be possible only with space telescopes, can also be done from the surface of our planet (observations for this study were carried out with a spectrograph installed on the 4-meter telescope at Calar Alto, Spain).

“These are exciting times for the search of atmospheric signatures in exoplanets,” says Christophe Lovis, senior lecturer at the the University of Geneva (UNIGE) and co-author of the study. “This result will enhance the interest of the scientific community for these instruments. Their number and their geographical distribution will allow us to cover the entire sky, in search for evaporating exoplanets,” concludes Lovis.

 

R. Allart et al. Spectrally resolved helium absorption from the extended atmosphere of a warm Neptune-mass exoplanet. Science, 2018 DOI: 10.1126/science.aat5879

Using spectroscopy, scientists were able to find helium in the escaping atmosphere of the planet — the first detection of this element in the atmosphere of an exoplanet. Credit: NASA, M. Kornmesser.

Astronomers find helium in exoplanet’s atmosphere for the first time

Using spectroscopy, scientists were able to find helium in the escaping atmosphere of the planet — the first detection of this element in the atmosphere of an exoplanet. Credit: NASA, M. Kornmesser.

Using spectroscopy, scientists were able to find helium in the escaping atmosphere of the planet — the first detection of this element in the atmosphere of an exoplanet. Credit: NASA, M. Kornmesser.

Helium is the second most abundant element in the universe, after hydrogen. For this reason, scientists have always presumed it would be one of the first elements they’d be able to detect in large exoplanets — alien worlds that orbit stars outside the Solar System. Using space telescopes like Kepler, scientists have confirmed thousands of exoplanets but none seem to have contained helium — until now.

Astronomers using the Hubble Space Telescope reported detecting the ubiquitous element on WASP-107b, a Jupiter-sized exoplanet located 200 light-years away from Earth. Despite its huge size, the exoplanet has an abnormally low density, having only 12% of Jupiter’s mass.

The international team of researchers was actually on the lookout for methane but the infrared light readings showed that the atmosphere of WASP-107b turns out to be filled with helium. What’s more, the astronomers were able to tell that the planet’s upper atmosphere extends for tens of thousands of miles into space due to the weak gravitational pull. For the same reason, the planet’s atmosphere is slowly eroding as gas escapes into space.

Perhaps helium is truly abundant in the atmosphere of exoplanets, particularly the large ones, as scientists have always presumed. Until now, the method of choice for detecting atmospheric gases relied on ultraviolet and optical wavelengths, which have their limitations. The new study shows that infrared detection methods are effective and worth pursuing more.

“The strong signal from helium we measured demonstrates a new technique to study upper layers of exoplanet atmospheres in a wider range of planets,” Jessica Spake, lead author of the study from the University of Exeter in the U.K, said in a statement.

“Current methods, which use ultraviolet light, are limited to the closest exoplanets. We know there is helium in the Earth’s upper atmosphere and this new technique may help us to detect atmospheres around Earth-sized exoplanets—which is very difficult with current technology.”

The findings were reported in the journal Nature.

Artist's representation of what a Y-class brown dwarf might look like.

Researchers spot the biggest brown dwarf ever, trailing at the edge of the Milky Way

An international research team has found the largest brown dwarf we’ve ever seen, and it has ‘the purest’ composition to boot. Known as SDSS J0104+1535, the dwarf trails at the edges of the Milky Way.

An artists' representation of a brown dwarf with polar auroras.

An artists’ representation of a brown dwarf with polar auroras.
Image credits NASA / JPL.

Brown dwarfs — they’re like stars, but without the spark of love. They’re much too big to be planets but they’re too small to ignite and sustain fusion, so they’re not (that) bright and warm and so on. Your coffee is probably warmer than some Y-class brown dwarfs, which sit on the lower end of their energy spectrum. The coldest such body we know of, a Y2 class known as WISE 0855−0714, is actually so cold (−48 to −13 degrees C / −55 to 8 degrees F) your tongue would stick to it if you could lick it.

But they can still become really massive, as an international team of researchers recently discovered: nestled among the oldest of stars in the galaxy at the halo of our Milky Way, some 750 light years away from the constellation Pisces, they have found a brown dwarf which seems to be 90 times more massive than Jupiter — making it the biggest, most massive brown dwarf we’ve ever seen.

Named SDSS J0104+1535, the body is also surprisingly homogeneous as far as chemistry is concerned. Starting from its optical and near-infrared spectrum measured using the European Southern Observatory’s Very Large Telescope, the team says that this star is “the most metal-poor and highest mass substellar object known to-date”, made up of an estimated 99.99% hydrogen and helium. This would make the 10-billion-year-old star some 250 times purer than the Sun.

Artist's representation of what a Y-class brown dwarf might look like.

Y u so cold?
Image credits NASA / JPL-Caltech.

 

“We really didn’t expect to see brown dwarfs that are this pure,” said Dr Zeng Hua Zhang of the Institute of Astrophysics in the Canary Islands, who led the team.

“Having found one though often suggests a much larger hitherto undiscovered population — I’d be very surprised if there aren’t many more similar objects out there waiting to be found.”

From its optical and infrared spectrum, measured using the Very Large Telescope, SDSS J0104+1535 has been classified as an L-type ultra-cool subdwarf — based on a classification scheme established by Dr Zhang.

The paper “Primeval very low-mass stars and brown dwarfs – II. The most metal-poor substellar object” has been published in the journal Monthly Notices of the Royal Astronomical Society.

Crystal structure of Na2He, resembling a three-dimensional checkerboard. The purple spheres represent sodium atoms, which are inside the green cubes that represent helium atoms. The red regions inside voids of the structure show areas where localized electron pairs reside. Illustration is provided courtesy of Artem R. Oganov.

Helium can, in fact, react with other elements to form a stable compound. Better re-write those textbooks

Crystal structure of Na2He, resembling a three-dimensional checkerboard. The purple spheres represent sodium atoms, which are inside the green cubes that represent helium atoms. The red regions inside voids of the structure show areas where localized electron pairs reside. Illustration is provided courtesy of Artem R. Oganov.

Crystal structure of Na2He, resembling a three-dimensional checkerboard. The purple spheres represent sodium atoms, which are inside the green cubes that represent helium atoms. The red regions inside voids of the structure show areas where localized electron pairs reside. Credit: Artem R. Oganov.

Helium is the second most abundant element in the universe, second only to hydrogen. Despite its virtual ubiquity, helium isn’t a team player, being totally unreactive with any other element, as any chemistry freshman will tell you. But while helium is by all accounts inert in Earth’s atmosphere, inside the planet’s core is a whole different matter. The extreme pressures cause helium to alter its chemistry allowing it to react with sodium, according to an international consortium of scientists.

The first of the noble elements

Helium is unreactive because it has a closed-shell electron configuration. Since it’s completely full, it’s not happy with sharing or ceding electrons. Such is the case for all noble gases, a select club that also includes neon, argon, krypton, xenon, and radon.

In the early days of experimental chemistry, scientists had thrown everything they had at these elements to spark a reaction but to no avail. In 1924, the Austrian Friedrich Paneth pronounced the consensus. “The unreactivity of the noble gas elements belongs to the surest of all experimental results,” he wrote.

This apparently decisive statement didn’t convince everyone, though, and along the years a number of brave or fool scientists, whichever pleases you, attempted to react noble elements. Finally, in 1962, British chemist Neil Bartlett, working at the University of British Columbia in Vancouver, Canada, succeeded in reacting Xenon with the compound platinum hexafluoride (PtF6), which was made only three years earlier by American chemists. The resulting compound XePtF6xenon hexafluoroplatinate — was the first noble-gas compound.

Many other compounds of Xenon and Krypton followed soon after. Then compounds of radon and, in 2000, argon too. In the same year, German researchers made a compound of xenon and gold, the latter being a noble metal which was supposed to be unreactive as well.

Helium, however, given its extremely stable electron configuration has evaded all other previous incursions.

Persistence is key

Taking cues from these earlier inspiring moments in chemistry, an international team of researchers crunched the numbers to see whether or not helium can react with anything. The team was led by Prof. Artem R. Oganov, a professor at Stony Brook University and head of Computational Materials Discovery laboratory at Moscow Institute of Physics and Technology.

Their computer models suggest that He can indeed form stable compounds, namely Na2He and Na2HeO. Initially, the results suggested that the Na2He compound consists of Na8 cubes, of which half were occupied by helium atoms and half were empty.

Ball-and-stick representation, left, and polyhedral representation, right, of chemical bonding analysis of the Na2He structure, where half of the Na8 cubes are occupied by He atoms (shown as polyhedra) and half by two electrons (shown as red spheres.). Pink and gray atoms represent Na and He, respectively. Credit: Ivan Popov/Utah State University

Ball-and-stick representation, left, and polyhedral representation, right, of chemical bonding analysis of the Na2He structure, where half of the Na8 cubes are occupied by He atoms (shown as polyhedra) and half by two electrons (shown as red spheres.). Pink and gray atoms represent Na and He, respectively. Credit: Ivan Popov/Utah State University

“Yet, when we performed chemical bonding analysis of these structures, we found each ’empty’ cube actually contained an eight-center, two-electron bond,” said Utah State University professor Alex Boldyrev. “This bond is what’s responsible for the stability of this enchanting compound.”

“As we explore the structure of this compound, we’re deciphering how this bond occurs and we predicted that, adding oxygen, we could create a similar compound,” said doctoral student Ivan Popov.

After the two He compounds were predicted, the researchers experimentally synthesized them using a diamond anvil cell at the Carnegie Institution for Science in Washington. The compound Na2He formed when the pressure reached 1.1 million times that of Earth’s atmospheric pressure. Predictions suggest the compound can remain stable even at pressures ten million times that. Na2HeO was found to be stable in the pressure range from 0.15 to 1.1 million bars.

“It’s not a real bond” in the sense of the ionic and covalent bonds you learned about in chemistry”, explained Popov. “But [the helium] does stabilize the structure. If you take those helium atoms away, the structure will not be stable.”

A similar technique was used to form metal hydrogen, news which we reported only last week.

Both compounds are ionic crystals — an electride to be precise — with similar structures. Na2He has a positively charged sublattice of sodium ions and a negatively charged sublattice of localized electron pair, which makes the compound an insulator. Na2He has negatively charged oxygen in the form of O2 instead of the electron pairs, as reported in Nature Chemistry. 

“The compound that we discovered is very peculiar: helium atoms do not actually form any chemical bonds, yet their presence fundamentally changes chemical interactions between sodium atoms, forces electrons to localize inside cubic voids of the structure and makes this material insulating,” says Xiao Dong, the first author of this work, who was a long-term visiting student in Oganov’s laboratory at the time when this work was done.

This is clearly exotic work. The findings illustrate how the ‘impossible’ is possible sometimes if you set your mind to it.

It was a good day for science!

Helium baloons

Your party is saved! Scientists find a massive stash of Helium beneath Tanzania

Helium baloons

What a waste. Credit: Pixabay

Scientists have warned for years that a helium shortage crisis is looming. While this is technically true, we just bought some time in delaying the inevitable after geophysicists discovered a new helium reserve in Tanzania, Africa.

Why Helium is so important

Most of us are familiar with helium balloons, but the gas is far more valuable than a cheap party trick. About 20 percent of all the processed helium in the world is used by the medical sector which depends on it to cool superconducting magnets for MRI machines. Liquid helium is also used to cool just about every important physics experiment, and is hence indispensable to scientific efforts.

Technically, helium is a renewable resource constantly being replenished by radioactive materials like uranium which eventually decay into lighter elements. But helium is in short supply accounting for only 5 parts per million in our atmosphere. Moreover, being lighter than air it leaches out into space. Coupled with extensive use, this means we’re using more helium than the planet is generating — yet another classic example of unsustainability.

According to a 2010 study, all of the known helium reserves should run out in the next 25 years. Bye, bye helium balloons — unless you’re prepared to pay hundreds of dollars for one.

We just bought some time, though. Speaking at the Goldschmidt geochemistry conference, researchers from Durham and Oxford University claimed they have identified a massive helium reserve in the East African Rift Valley, a highly active volcanic area in Tanzania.

“We sampled helium gas (and nitrogen) just bubbling out of the ground in the Tanzanian East African Rift valley. By combining our understanding of helium geochemistry with seismic images of gas trapping structures, independent experts have calculated a probable resource of 54 billion cubic feet (BCf) in just one part of the rift valley.” Chris Ballentine, a researcher on the project said. “This is enough to fill over 1.2 million medical MRI scanners. To put this discovery into perspective, global consumption of helium is about 8 BCf per year and the United States Federal Helium Reserve, which is the world’s largest supplier, has a current reserve of just 24.2 BCf. Total known reserves in the USA are around 153 BCf. This is a game changer for the future security of society’s helium needs and similar finds in the future may not be far away.”

If the findings are confirmed, then the helium stockpile from Tanzania is at least 50 times bigger than the previous record holder, a one-billion-cubic-feet reserve near Amarillo, Texas.

Other such stockpiles might be found elsewhere in the world, where volcanic activity is strong. This is how the researchers, who partnered with a specialized Norwegian company called Helium One, discovered the reserve in the first place.

“We show that volcanoes in the Rift play an important role in the formation of viable helium reserves. Volcanic activity likely provides the heat necessary to release the helium accumulated in ancient crustal rocks. However, if gas traps are located too close to a given volcano, they run the risk of helium being heavily diluted by volcanic gases such as carbon dioxide, just as we see in thermal springs from the region. We are now working to identify the ‘goldilocks-zone’ between the ancient crust and the modern volcanoes where the balance between helium release and volcanic dilution is ‘just right’,” said Diveena Danabalan, lead author of the research.

helium balloons

How we’re wasting all our precious helium. A call for recycling

helium balloons

Helium balloons should be banned in light of our helium crisis. Credit: Pixabay.

Most people don’t know this but helium — the familiar inert gas we all use to inflate party balloons — is running out at an astonishing rate. Helium is the second lightest chemical element in the Universe, so light that it can’t be kept by Earth’s atmosphere as it floats into space whenever it gets the chance to escape. Despite helium is non-renewable, the element is being currently squandered for basically nothing at all around the world because of bad policies, this despite the incredible value it poses to science and humanity.

Why we need helium

Currently, helium is indispensable for such applications like electronics, medicine, defense, minerals and space exploration. Forget your party balloons, without helium hospitals would have no chance in using their MRI scanners that are cooled by the gas in liquid form. Helium in its liquid state can only exist at around -270 degrees celsius or so, and its the best option scientists currently have to cool down matter to enable the study of quantum effects, which would otherwise be disturbed by the vibration of atoms at warmer temperatures. The Large Hadron Collider also uses liquid helium for cooling, and without it, many of its discoveries like the latest Higgs boson would have been more difficult if not impossible to make.

Helium is an inert gas that, while abundant in the universe, is very rare on Earth, making up just 5 parts per million of the atmosphere. Most of the helium we use today is found in gas pockets trapped inside the planet, typically obtained as a by-product of oil extraction. However, we can’t artificially obtain helium. Once it’s gone, it’s gone for good, baby!

Helium is made either by the nuclear fusion process in the Sun or by the slow and steady radioactive decay of terrestrial rock, which accounts for all of the Earth’s store of the gas. So, despite the Earth took 4.7 billion years to slowly build its current helium reserves, at the current rate we could end up depleting all of it in a generation’s time, according to Nobel laureate Robert Richardson, professor of physics at Cornell University in Ithaca, New York.

So, despite helium has proven itself to be an extremely valuable commodity time and time again, people seem to be keen on wasting it. Why? Well for one bad policies, and it all started going downhill once with an absurd law passed in the United States in 1996 which basically mandated that all helium reserves  in the porous rock of a disused natural gasfield 30 miles north of Amarill — billion cubic metres or about half of the world’s reserves – had to ALL be sold by 2015 in order to make-up for the initial investment that went in building up the reserve. The law stipulated the amount of helium sold off each year should follow a straight line with the same amount being sold each year, irrespective of the global demand for it.  What this meant is that the market was simply swelled by this immense influx of helium making it too cheap.

“As a result of that Act, helium is far too cheap and is not treated as a precious resource,” Professor Richardson said. “It’s being squandered.”

The world could be out of helium in just 30 years!

Today, helium is far too cheap for it to be worth recycling. According to Richardson, the price should rise by between 20- and 50-fold to make recycling more worthwhile. Even NASA makes no attempt to recycle the helium used to clean is rocket fuel tanks, one of the single biggest uses of the gas.

The latest call to action on the issue comes from Australia, where recently a new helium recycling facility at Macquarie University in Sydney was launched this week (Jul 30, 2013). Dr Cathy Foley, chief of CSIRO Materials Science and Engineering made the comments ahead of the launch:

“It’s a precious resource which we’re just letting go,” says Foley. “It’s critical for a lot of scientific experiments.”

“And once it’s all gone, it’s not easy to make helium. You have to either do a nuclear reaction or go to the Moon to get it.”

Foley says while CSIRO has been capturing and re-liquefying helium for many years, most laboratories just allow their used helium to escape. The university has a number of magnetoencephalography (MEG) machines that study magnetic fields in the brain to understand brain processes such as language learning. To detect small magnetic fields, these machines use a super-conducting device, which needs to be cooled to very low temperatures. She says CSIRO has helped develop a system for the MEG machines that can capture 90 percent of spent helium and re-liquefy it quite simply.

“When you buy a helium balloon, you might get it for $3.50, but the helium in that is really worth about $35 so it’s seriously underpriced,” says Foley.

Professor Brent McInnes, from Curtin University, agrees.

“We are going to see helium rationing in the near future. It already exists in the scientific market today,” McInnes told a briefing held by the Australian Science Media Centre yesterday.

“Then we’ll know what the true cost of helium in party balloons is,” he says, adding that use of the gas in party balloons is actually a very small sector of the helium market.

Curious spiral spotted by ALMA around red giant star R Sculptoris (data visualisation). (c) ALMA

Star dies in a dazzling 3-D spiral light show – might surface new details on star evolution

Curious spiral spotted by ALMA around red giant star R Sculptoris (data visualisation). (c) ALMA

Curious spiral spotted by ALMA around red giant star R Sculptoris (data visualisation). (c) ALMA

Astronomers have come across a peculiar phenomenon after observing a distant dying star that sheds matter in a three-dimensional spirally pattern due to pulsations at its core. This is a totally atypical behavior, which scientists have yet to encounter before, one that might shed new light on star evolution.

The red star called R Sculptoris, located 1500 light years away in the constellation of Sculptor, is currently at the last stages of its life, shedding shells of matter, driven out by solar winds created by the high temperature gradients at its core. The matter blown out will accumulate into planetary nebulae over the course of million of years, which provides the basic material for other stars to form – a universal cycle. However, R Sculptoris doesn’t simply shell out material, it does it in 3D spiral, and while the exact mechanics of this behavior have yet to be resolved, we as simple observers can only rejoice at its beauty.

The astronomers used only half of the 66 high precision antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) observatory to peel through the guts of the star. Everybody was surprised at what they saw – “we’ve seen shells around this kind of star before, but this is the first time we’ve ever seen a spiral of material coming out from a star, together with a surrounding shell,” said Matthias Maercker, from the Argelander Institute for Astronomy, University of Bonn, Germany.

Further observations of R Sculptoris show that it suffered a thermal pulse event some 1800 years ago that lasted for about 200 years –  a thermonuclear convulsion that happens deep in the star’s core. At his stage during a star’s last moments, helium fuses into heavier elements, releasing a great of energy in the process, while also causing a shedding of high density material from the red star’s atmosphere.

But why the spirally pattern? Well, the astronomers’ best bet is that the phenomenon is triggered by a neighboring, high proximity star, whose gravity drives matter away. This hasn’t been confirmed though, since such a star has yet to be observed.

“It’s really gratifying to see this new view of a process that we’ve known about for some time but never seen in such detail,” said astronomer Mark Morris of UCLA, who was not involved with the work.

R Sculptoris is important for many reasons. For one, it provides real data the researchers can use to compare with their computer models of red star late stage matter outflow. They already found, for instance, that more material is blowing out than was expected from simulations. Also, R Sculptoris is very similar to our sun, and most likely it will suffer a similar fate 5 billion years in the future when it’s expected to collapse.

Below you can watch a video that exhibits the internal structure of the star, showing slices through data taken at a slightly different frequency.


Findings were reported in the journal Nature.

via Wired Science

NASA's Lunar Reconnaissance Orbiter i

Helium presence confirmed on the Moon’s thin atmosphere

According to recent findings as a result of observations from NASA’s Lunar Reconnaissance Orbiter (LRO), it seems like the moon’s pale atmosphere contains helium, a fact in question for some forty years since the first hints were discovered on the lunar surface during the Apollo missions.

NASA's Lunar Reconnaissance Orbiter i

NASA’s Lunar Reconnaissance Orbiter. (c) NASA

The moon is often considered not to have an atmosphere, and for practical reasons Earth’s satellite is many times regarded as being surrounded in an envelope of vacuum. However, scientists frequently refer to what’s called the “lunar atmosphere” – a thin, very fragile layer of gaseous atomic and molecular particles. However, this is atmosphere is so tiny, that’s often negligible. How tiny? It’s less than one hundred trillionth of Earth’s atmospheric density at sea level.

This means that it’s surface offers practically zero protection against solar radiation exposure and meteors can simply hit the moon without encountering any resistance. Still, tiny as it is, the moon has an atmosphere, and scientists have been studying it for a very long time.

The latest findings from the LRO is set to confirm the very first evidence of the presence of Helium in the moon’s atmosphere by the Lunar Atmosphere Composition Experiment (LACE), which was deployed by moonwalking Apollo 17 astronauts in 1972. The team of researchers involved the observations,  used the spectrometer aboard the orbiter to examine the far ultraviolet emissions visible in the atmosphere, detecting helium over a period spanning more than 50 orbits. Various techniques were used to measure the Helium levels on the moon’s surface in order to rule out possible interplanetary readings.

How does Helium get on moon in first place?

“The question now becomes, does the helium originate from inside the moon — for example, due to radioactive decay in rocks — or from an exterior source, such as the solar wind?” Alan Stern, of the Southwest Research Institute in Boulder, Colo., said in a statement. Stern is principal investigator of LRO’s Lyman Alpha Mapping Project spectrometer, or LAMP.

Radioactive decay within the crust and mantle leads to a reaction which releases helium and radon. However, the major proportion of helium on the moon’s surface is most likely due to solar wind and light. Also, micrometeorite bombardment is also considered a factor.

“If we find the solar wind is responsible, that will teach us a lot about how the same process works in other airless bodies,” Stern said.

The initial 1972 experiments  showed an increase in helium abundance as night progressed. Scientists believe this is due to the phenomenon of atmospheric cooling which concentrates atoms at lower altitudes. Most likely, these findings will be followed up by NASA scientists.

Artist's impression of gas around a forming galaxy in a large computer simulation. The pristine gas detected by astronomers could lie in one of the filamentary regions. (c) Ceverino, Dekel, and Primack

Elemental gas clouds formed minutes after the Big Bang found

Artist's impression of gas around a forming galaxy in a large computer simulation. The pristine gas detected by astronomers could lie in one of the filamentary regions. (c) Ceverino, Dekel, and Primack

Artist's impression of gas around a forming galaxy in a large computer simulation. The pristine gas detected by astronomers could lie in one of the filamentary regions. (c) Ceverino, Dekel, and Primack

One of the fundamental backbones of the Big Bang theory states that after the rapid expansion of the Universe only the lightest elements were formed. A group of scientists stumbled across an amazing discovery recently when they found a gas cloud dating from the time of the early Universe exclusively made out of hydrogen and helium, proving another solid evidence that supports the current Universe formation model. This is the first time scientists have been able to observe an area without any metallic elements, and thus peek into the early universe.

The two gas clouds weren’t observed directly, but by means of spectral analysis of the light emitted by a distant quasar, which in its travels also happened to pass through these primordial traces of the Universe, estimated at being 13.7 billion years old. The location of the clouds has been estimated at around 2 billion light years away, however they were formed just minutes after the Bing Bang. Amazingly enough, these clouds remained unpolluted by other elements for 2 billion years.

This isn’t however the oldest trace of the Universe found so far. Other discoveries have found objects just one billion years old, but this particular research is of great importance, since it enforces one of the fundamental principles that constitute the Big Bang model, which states that only the first two elements on the periodic table, hydrogen and helium, existed in the very early universe.

“This is very good news because the existence of gas without metal has been predicted by the big bang theory but never observed,” UC Santa Cruz doctoral student Michele Fumagalli, who helped on the study, says. “So the fact that we are seeing these gases there is now empirical evidence that this theory is correct.”

It certainly surprised Christopher Howk, a physics professor at the University of Notre Dame, who wasn’t involved in the study. “I actually was kind of shocked that they found this, because I had kind of given up hope that they would find this anytime soon, especially the way they did.”

All the other heavy elements, like metals, came millions and billions of years later inside of stars.

“When a massive star runs out of its fuel it explodes in a supernovae,” John O’Meara, a professor at Saint Michael’s College in Vermont who was an author on the new study says. “The explosions are so violent that it kicks this stuff [heavy elements] out of the galaxy.”

Incited by this phenomenal find, scientists now are poised to enlist on primordial gas hunts, so that similar pockets of elemental gas can be studied. The research appears in this week’s Science. 

The star that should not exist

If you look at this picture, you will probably see what can only be described as an unremarkable, even faint star. But this ancient star, in the constellation of Leo (The Lion), called SDSS J102915+172927 has astrophysicists scratching their heads, searching for new answers.

A team of European astronomers using ESO’s Very Large Telescope (VLT) to track down a star in the Milky Way that many thought was impossible: it is built only out of Hydrogen and Helium, with extremely low quantitites of other elements. This freakish composition puts it in the ‘forbidden zone’ of the widely accepted star formation theory, meaning that if the theory was correct, this star shouldn’t have formed.

The star has the lowest amounts of elements heavier than Helium ever to be discovered – 20.000 times lower than our Sun. It is also much smaller and older than our Sun – estimated at 13 billion years.

“A widely accepted theory predicts that stars like this, with low mass and extremely low quantities of metals, shouldn’t exist because the clouds of material from which they formed could never have condensed,” said Elisabetta Caffau (Zentrum fur Astronomie der Universität Heidelberg, Germany and Observatoire de Paris, France), lead author of the paper. “It was surprising to find, for the first time, a star in this ‘forbidden zone’, and it means we may have to revisit some of the star formation models.”

Yet here it is, looking all fine and dandy! Cosmologists believe that Hydrogen and Helium (and a little Lithium), the lightest elements, were created shortly after the Big Bang, while the others elements we see today were formed afterwards in stars. Supernova explosions spread this material across the interstellar medium, and new stars form in this enrichened environment, and therefore, the proportion of this material can give us a good dea about how old the star is.

“The star we have studied is extremely metal-poor, meaning it is very primitive. It could be one of the oldest stars ever found,” adds Lorenzo Monaco (ESO, Chile), also involved in the study.

Also, extremely surprising was the almost total absence of Lithium. Researchers believe that this star could have the same composition as the Universe in its early days; however, the star had 50 times less Lithium than you would expect in those days.

“It is a mystery how the lithium that formed just after the beginning of the Universe was destroyed in this star.” Bonifacio added.

Either way, astronomers now believe that this weird star is not the only one of its kind, so they are searching for more, using the VLT to find more examples and explain the nature of this weird star.

First frictionless superfluid molecules created

Superfluidity is a weird property, by all standards. Basically it is a state of matter in which all the viscosity of a fluid vanishes; what happes is you take some atoms, and you chill them, and then chill them some more, until they get close to absolute zero (-273.15 degrees Celsius, the temperature below which nothing can exist). After this, the atoms creep up the walls or stay still while the bowl they sit in rotates.

Superfluidity is only observed when temperatures get close to absolute zero; once you get that, the helium or hydrogen atoms in case started to behave as a single quantum object rather than individual objects. Basically, all the friction between atoms disappears, as well as the friction between atoms and other objects, creating what is known as a superfluid.

Robert McKellar of the National Research Council of Canada in Ottawa and colleagues turned to hydrogen, which exists as pairs of atoms. The result was that they managed to obtain about 85% superfluidity. Hydrogen is only the second element to behave in such a way, and researchers believe this experiment could prove to be useful in understanding the general properties of superfluids, rather than having an utility in itself.