Tag Archives: magnetic

New brain stimulation technique cured 80% of major depression cases during trial run

We might soon have a reliable treatment for severe depression. New research at the Stanford University School of Medicine reports that a new type of magnetic brain stimulation was successful in treating almost 80% of participants with this condition.

Image via Pixabay.

The treatment approach is known as the Stanford Accelerated Intelligent Neuromodulation Therapy (SAINT), or Stanford neuromodulation therapy for short. It is an intensive, individualized transcranial magnetic stimulation therapy, and it shows great promise against severe depression — so far, in controlled trials. While effective, there are some side effects to this treatment: temporary fatigue and headaches.

All in all, the authors are confident that the benefits far outweigh the risks with SAINT, and they hope their work will pave the way towards new treatment options for many patients around the world.

A promising approach

“It works well, it works quickly and it’s noninvasive,” said Nolan Williams, MD, an assistant professor of psychiatry and behavioral sciences, and senior author of the study. “It could be a game changer.”

The study included 29 participants with treatment-resistant depression. They ranged in age from 22 to 80, and had suffered from depression for an average of nine years at the time of the study. All of these cases have proven to be resistant to medication. Participants who were on medication during the study maintained their regular dosage, but those who weren’t did not start any course during the treatment period.

They were split into two groups, one of which received the SAINT treatment, with the other receiving a placebo procedure that mimicked it. Five days into the treatment, 78.6% of the participants in the SAINT group no longer qualified for depression as judged using several evaluation efforts. The effects were sustained over time after the treatment had ceased, the authors note.

Current transcranial magnetic stimulation options that carry the approval of the Food and Drug Administration require six weeks of daily sessions, the authors explain. It’s effective in about half the patients who undergo such treatments, and only about a third show remission from depression following the treatment.

SAINT builds on these approaches by first targeting the pulses in different areas tailored after each patient’s neurocircuitry, and by delivering a greater number of magnetic pulses at a higher frequency.

In order to determine the particularities of each patient’s dorsolateral prefrontal cortex — an area of the brain involved in regulating executive functions –, the authors performed an MRI analysis on each participant before the start of the study. Their goal was to find the exact subregion in the brain that had the strongest functional link to the subgenual cingulate. This structure has been documented to exhibit heightened levels of activity in people experiencing depression. The goal of the magnetic stimulation treatment is to strengthen the link between the two areas in order to allow the dorsolateral prefrontal cortex to better control the activity in the subgenual cingulate.

The density of the pulses delivered in this trial was three times greater than that of currently-approved treatments: 1,800 per session compared to the regular number of 600. Finally, instead of providing one treatment session per day, the team gave their participants 10 10-minute treatments, with 50-minute breaks in between. The control group underwent ‘treatment’ with a magnetic coil that mimics the experience of the magnetic pulses.

Both groups wore noise-canceling earphones and received a topical ointment to dull sensation before each session.

Four weeks after the trial, 12 of the 14 participants in the experimental group showed improvements in their symptoms. According to FDA criteria for remission, 11 of them were officially cured of depression. In the control group, only 2 out of 15 patients met the criteria for remission.

The team is particularly interested in using SAINT to treat patients who are at a crisis point. Their study revealed that participants felt better and had attenuated symptoms within days of starting SAINT; this timeframe is much shorter than what is seen with medication, where improvements can take up to a month or more.

“We want to get this into emergency departments and psychiatric wards where we can treat people who are in a psychiatric emergency,” Williams said. “The period right after hospitalization is when there’s the highest risk of suicide.”

The paper “Stanford Neuromodulation Therapy (SNT): A Double-Blind Randomized Controlled Trial” has been published in the American Journal of Psychiatry.

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.

Our Sun’s magnetic field might form a ‘deflated croissant’, says NASA

New research at NASA developed a new prediction for the shape of the heliosphere, the magnetic bubble encasing our Solar System. But their result is not at all similar to the comet-like shape we’ve envisioned so far — in fact, it’s more of a “deflated croissant”, the agency reports.

An updated model of the heliosphere (seen in yellow).
Credits: Opher, et al. / NASA.

Outer space may be void, but it’s not completely empty. Magnetic fields and ionized gases permeate the galactic stretches between stars, and this substance is called the interstellar medium. It’s pushed back by the solar system’s magnetic ‘shield’, the heliosphere, just like Earth is protected from solar radiation by its own magnetic field. Using new data obtained from NASA’s crafts, the agency has developed a new model to describe the shape of this heliosphere.

Pastry-like shield

The shape of the heliosphere has been a point of interest of researchers for quite some time now. Traditionally, it is believed to have a comet-like shape with a long tail and a rounded leading edge (the ‘nose’). We believed it to be shaped in this fashion due to the Solar System zipping around through space.

However, researchers are now proposing an alternate model — the deflated croissant.

The shape of this heliosphere is very difficult to measure from within (where we are). For starters, it’s much too large for our sensors to be able to pick it up: its edge is around ten billion miles from Earth, according to NASA. Our only sources of direct data regarding it come from the two Voyager spacecraft that are well on their way to deep space.

We do, however, study this structure indirectly by capturing charged particles incoming to Earth from distant parts of the galaxy (cosmic rays). Alongside radiation formed by the Sun, these bounce back from the heliosphere, changing their physical properties in the process — and by studying them we can infer data about the heliosphere. In essence, we use this radiation the way a radar uses radio waves. This process is the one used by NASA’s Interstellar Boundary Explorer, or IBEX.

The latest iteration of the heliosphere model produced by NASA draws on data from the Voyager spacecrafts, the Cassini mission (to Jupiter), and the New Horizons mission (to Jupiter and Pluto). Using data from several points of the solar system allowed them to sample different types of particles.

Artist’s recreation of how the heliosphere blocks out cosmic rays (bright streaks in the image).
Image credits: NASA’s Goddard Space Flight Center / Conceptual Image Lab.

“There are two fluids mixed together. You have one component that is very cold and one component that is much hotter, the pick-up ions,” said Merav Opher, a professor of astronomy at Boston University, director of the DRIVE Science Center at Boston University focused on the challenge, and lead author of the new research.

“If you have some cold fluid and hot fluid, and you put them in space, they won’t mix — they will evolve mostly separately. What we did was separate these two components of the solar wind and model the resulting 3D shape of the heliosphere.”

Modeling the behavior of these particles separately allowed the team to estimate the shape of the heliosphere. The end result was a “deflated croissant” shape, with a central body and two jets that trail chaotically behind it.

“Because the pick-up ions dominate the thermodynamics, everything is very spherical. But because they leave the system very quickly beyond the termination shock, the whole heliosphere deflates,” said Opher.

The shape of the heliosphere is of great academic interest, but its activity is a boon for us all. It blocks about 75% of incoming cosmic rays, which would otherwise make their way into the solar system. While our planet is protected by a magnetic field and an atmosphere, astronauts and spacecraft are not.

This shield then, despite being shaped like a disappointing pastry, may be the only thing that allowed us to ever get off the planet and into space without being deep-fried by radiation in the process.

By knowing more about the heliosphere, we can also better estimate which alien planets are candidates for life.

New magnetic brain stimulation technique relieved depression in 90% of the participants in a small-scale study

Researchers at the Stanford University School of Medicine have developed a form of magnetic brain stimulation that could ‘rapidly’ relieve symptoms of severe depression in 90% of participants in a small study.

Image via Pxhere.

Although the findings are limited by the small sample size so far, the team is working on a larger, double-blind trial to test the approach; in this trial, half of the patients will receive similar electromagnetic stimulation, while the other half will receive fake treatment. In this second trial, the team hopes to prove that their approach will be effective in treating people whose conditions are resistant to medication, talk therapy, or other forms of electromagnetic stimulation.

The real positive vibes

“There’s never been a therapy for treatment-resistant depression that’s broken 55% remission rates in open-label testing,” said Nolan Williams, MD, assistant professor of psychiatry and behavioral sciences and a senior author of the study. “Electroconvulsive therapy is thought to be the gold standard, but it has only an average 48% remission rate in treatment-resistant depression. No one expected these kinds of results.”

The method was christened Stanford Accelerated Intelligent Neuromodulation Therapy, or SAINT, and is a form of transcranial magnetic stimulation, an approach currently approved by the Food and Drug Administration for treatment for depression. Transcranial magnetic stimulation involves the use of a magnetic coil placed on the scalp to excite a region of the brain — in this case, those involved in depression.

Compared to other similar approaches, the SAINT method uses more magnetic pulses (1,800 pulses per session instead of the traditional 600), which helps speed up the pace of treatment, and focuses them depending on each patient’s particular neural architecture. Study participants underwent an accelerated treatment program compared to similar treatment approaches, 10 sessions per day of 10-minute treatments, with 50-minute breaks in between.

In their trial study, the team worked with 21 participants with severe depression — as determined by several diagnostic tests — which proved resistant to medication, FDA-approved transcranial magnetic stimulation, or electroconvulsive therapy. After receiving treatment, 19 of them scored within the nondepressed range, the team explains. All of the participants reported having suicidal thoughts before treatment, but none of them reported such thoughts afterward.

“There was a constant chattering in my brain: It was my own voice talking about depression, agony, hopelessness,” explains Deirdre Lehman, 60, one of the participants of the study. “I told my husband, ‘I’m going down and I’m heading toward suicide.’ There seemed to be no other option.”

There were some side effects of this treatment, but they were relatively minor: fatigue and some physical discomfort during treatment.

“By the third round, the chatter started to ease,” she said. “By lunch, I could look my husband in the eye. With each session, the chatter got less and less until it was completely quiet.”

“That was the most peace there’s been in my brain since I was 16 and started down the path to bipolar disorder.”

Although Lehman’s scores indicated that she was no longer depressed after a single day of therapy, it took up to five days for other participants to see the same results. Postdoctoral researcher Eleanor Cole, Ph.D., a lead author of the study, says that the “less treatment-resistant participants are, the longer the treatment lasts”.

The team evaluated each participant’s cognitive functions before and after treatment to ensure safety, and found no negative effects. One month after the therapy, 60% of participants were still in remission from depression. Follow-up studies are underway to determine the duration of the antidepressant effects, the team adds.

The researchers plan to study the effectiveness of SAINT on other conditions, such as obsessive-compulsive disorder, addiction, and autism spectrum disorders.

The paper “Stanford Accelerated Intelligent Neuromodulation Therapy for Treatment-Resistant Depression” has been published in the American Journal of Psychiatry.

Sunset.

Massive solar storms are naturally-recurring events, study finds — and we’re unprepared for them

Solar storms can be even more powerful than what our measurements so far have indicated — and we’re still very unprepared.

Sunset.

Image via Pixabay.

Although our planet’s magnetic field keeps us blissfully unaware of it, the Earth is constantly being pelted with cosmic particles. Sometimes, however — during events known as solar storms, caused by explosions on the sun’s surface — this stream of particles turns into a deluge and breaks through that magnetic field.

Research over the last 70 years or so has revealed that these events can threaten the integrity of our technological infrastructure. Electrical grids, various communication infrastructure, satellites, and air traffic can all be floored by such storms. We’ve seen extensive power cuts take place in Quebec, Canada (1989) and Malmö, Sweden (2003) following such events, for example.

Now, new research shows that we’ve underestimated the hazards posed by solar storms — the authors report that we’ve underestimated just how powerful they can become.

‘Tis but a drizzle!

“If that solar storm had occurred today, it could have had severe effects on our high-tech society,” says Raimund Muscheler, professor of geology at Lund University and co-author of the study. “That’s why we must increase society’s protection again solar storms.”

Up to now, researchers have used direct instrumental observations to study solar storms. But the new study reports that these observations likely underestimated how violent the events can become. The paper, led by researchers at Lund University, analyzed ice cores recovered from Greenland to study past solar storms. These cores formed over the last 100,000 years or so, and have captured evidence of storms over that time.

According to the team, the cores recorded a very powerful solar storm occurring in 600 BCE. Also drawing on data recovered from the growth rings of ancient trees, the team pinpointed two further (and powerful) solar storms that took place in 775 and 994 CE.

The result thus showcases that, although rare, massive solar storms are a naturally recurring part of solar activity.

This finding should motivate us to review the possibility that a similar event will take place sooner or later — and we should prepare. Both the Quebec and Malmö incidents show how deeply massive solar storms can impact our technology, and how vulnerable our society is to them today.

“Our research suggests that the risks are currently underestimated. We need to be better prepared,” Muscheler concludes.

The paper “Multiradionuclide evidence for an extreme solar proton event around 2,610 B.P. (∼660 BC)” has been published in the journal Proceedings of the National Academy of Sciences.

Magnetic lines.

Earth’s inner core became solid just in time to save the planet

The Earth’s solid core likely formed about 565 million years ago, new research reveals — saving Earth’s magnetic shield in the process.

Magnetic lines.

Image credits Windell Oskay / Flickr.

Earth’s magnetic field forms a veritable bulwark against charged particles coming from space — such as solar wind and rays of cosmic radiation — that would otherwise turn us all to crispy mush. It also safeguards Earth’s atmosphere, which would be flayed little by little by these same solar winds in its absence. So if you enjoy breathing, you should be a big fan of the Earth’s magnetic field.

Our planet hasn’t always enjoyed the magnetic field protection of today, however. New research suggests that it’s only been around for roughly 565 million years.

Restarting the dynamo

The Earth’s magnetic field was at its lowest intensity around that time, the authors of a new study report. This suggests our planet’s internal dynamo was close to collapsing at that date (since this dynamo is what generates the planet’s magnetic field). The formation of Earth’s solid inner core was the one event that could strengthen this geomagnetic field, so this could not have happened yet.

As such, the team proposes that the planet’s inner core had begun to solidify around this time, although the process was not complete. These results should help refine our current estimates of when Earth’s inner core solidified. Currently, these estimates range between 2.5 billion and 500 million years ago.

For the study, John Tarduno and colleagues measured the geomagnetic field’s past intensity and direction. They did this by looking at tiny magnetic inclusions found within single crystals of plagioclase and clinopyroxene formed 565 million years ago in what is now Canada’s eastern Quebec. Think of these inclusions — usually iron compounds — as tiny compass needles, aligning themselves to the magnetic field as the crystals formed. By studying them, the team could determine the direction and intensity of the magnetic field at the date of the crystals’ formation.

They found unprecedentedly low geomagnetic field intensities. From this, they inferred that there was a high frequency of magnetic reversals at that time, suggesting that the geodynamo was on the point of collapsing. Iron solidifying at the (fledgling) inner core boundary would have injected significant energy into the dynamo system by driving the currents of liquid metal that generate the magnetic field. Computer simulations predicted that this energy boost would be preserved in the rock record, which determines the team to look for evidence in ancient crystals.

In a News & Views article detailing the studies, Peter Driscoll writes that “the nucleation of the inner core may have occurred right in the nick of time to recharge the geodynamo and save Earth’s magnetic shield.”

The paper “Young inner core inferred from Ediacaran ultra-low geomagnetic field intensity” has been published in the journal Nature.

Jupiter magnetic field.

Jupiter’s magnetic field is extremely bizarre, potentially due to unknown processes in its core

Jupiter’s magnetic field is crazy!

Jupiter, Io.

Jupiter and Io, one of its many moons.
Image via Pixabay.

The first map of the Jovian magnetic field has been compiled by an international team of researchers — and heads are still being scratched over it. The gas giants’ magnetic field is unlike anything we’ve ever seen before, hinting at unknown processes going on beneath its surface.

King of the gods

It didn’t come as much of a surprise to any researcher that Jupiter’s magnetic field is in a class of its own. While the gas giant boasts 11 times the diameter of our planet, it’s magnetic field is over 20,000 times as strong. It’s also much larger and has several complex features that have no counterpart in our own planet’s magnetic signature. These features, as far as we can tell, may stem from Jupiter’s rapid rotation and large liquid metallic hydrogen interior.

New data beamed back by the Juno spacecraft — which is still busy orbiting around the planet’s poles — allowed researchers from the US and Denmark to study this magnetic field much more closely than ever before. Starting from this data, which was recovered during eight orbits, they mapped the magnetic field in unprecedented detail at depths up to 10,000 kilometers (6,214 miles). Instead of making things more clear, however, the wealth of data only created further confusion. Take a look:

Jupiter magnetic field.

Image credits Moore et al., 2018, Nature.

Jupiter’s magnetic field emerges from a broad area close to its North pole (red on the image above) and re-enters around the South pole — so far, not especially surprising. What is very surprising, however, is that part of the magnetic field re-enters through a highly concentrated region just south of the equator — an area the team calls the Great Blue Spot.

The field is much weaker outside of these areas (grey-blue in the image above).

Earth’s magnetic field is dipolar. The field emerges from the South pole, re-enters through the North pole, and runs through the center of the planet. There are small non-dipolar components, but they’re relatively evenly spread out across the two hemispheres and they’re nowhere near as massive as the Great Blue Spot.

None of it prepared us for Jupiter’s hectic magnetic display.

“Before the Juno mission, our best maps of Jupiter’s field resembled Earth’s field,” planetary scientist Kimberly Moore of Harvard University told Newsweek. “The main surprise was that Jupiter’s field is so simple in one hemisphere and so complicated in the other. None of the existing models predicted a field like that.”

Juptier magnetic full.

Image credits

The lop-sided nature of Jupiter’s magnetic field points to yet-undiscovered processes under the surface. Magnetic fields are the product of churning flows of conductive liquids inside a planet. As the planet rotates, these liquids create magnetic fields — just like a dynamo.

Earth’s ‘dynamo’ is encased by a solid crust; the team believes their results suggest Jupiter’s dynamo lacks this casing. One of the models they propose envisions Jupiter’s core not as a solid, but as a slush — a mixture of rock and ice partially dissolved in liquid metallic hydrogen. Such a structure could create layers that would result in an asymmetrical magnetic field, they explain.

Another possibility would be that helium rains on the planet work to destabilize the field. This scenario, however, fails to satisfactorily explain the asymmetry seen in the magnetic field.

Juno is still orbiting Jupiter and will continue for quite some time. The team hopes to use further observations to better understand the magnetic field they’ve uncovered.

The paper “A complex dynamo inferred from the hemispheric dichotomy of Jupiter’s magnetic field” has been published in the journal Nature.

Test tube oils.

Nanoparticle treatment developed to scrub water clean of oil pollution

New research from the Rice University may hold the key to scrubbing water clean of oily pollutants.

Test tube oils.

The team developed nanoparticles that draw in the bulk of the oil and are then attracted to the magnet, as demonstrated here.
Image credits Jeff Fitlow / Rice University.

Water and oil don’t mix; except when they do. While the two fluids tend to separate readily, they’re able to mix just well enough to bind together. We call the resulting mixture an ’emulsion’. Not very dangerous in your kitchen — mayonnaise, for example, is an emulsion — but the phenomenon can cause problems in production water from oil wells. ‘Produced water’ comes from oil wells along with crude.

Looking for a way to scrub water clean in such cases, researchers from the Rice University have developed a nanoparticle-based solution that can remove 99% of the emulsified oil left over from oil wells.

The solution relies on magnetic nanoparticles that can attract oil droplets suspended in production water. The approach can scrub even those drops of oils that existing processes simply can’t remove.

Crude mixtures

Produced water is often laced with surfactants and other chemical compounds. These compounds are pumped into a crude oil reservoir to reduce the crude’s viscosity and help with extraction.

Now, believe it or not, you have some surfactants (surface acting substances) in your house; at least a bottle or a block of the stuff. You call it ‘soap‘. Soap helps you get clean by forcing water and fats (such as oils) to mix. One end of the soap molecule is hydrophilic (it ‘likes’ water) while the other end is hydrophobic (it ‘fears’ water). The hydrophilic end sports a water-soluble molecule that binds to water molecules, while the other end boasts a molecule that’s soluble in fats. Once each end has tied to the compounds of their affection, the soap molecule acts as a chain linking fat to water.

Sodium Stearate.

The chemical structure of sodium stearate, the main ingredient in soaps. The O-Na bond forms the hydrophilic ‘head’, while the tail represents the hydrophobic area.
Image credits Smokefoot / Wikimedia.

In an oil well, surfactants force the crude to form stable emulsions with water. Because this emulsion is less viscous than the crude alone, it’s more easily pumped by derricks up to the surface. Most of the crude can be separated and then extracted from such emulsions. A fraction of about 5% is never or almost never recovered, and remains tied to the water.

“Injected chemicals and natural surfactants in crude oil can oftentimes chemically stabilize the oil-water interface, leading to small droplets of oil in water which are challenging to break up,” said Sibani Lisa Biswal, paper co-author and an associate professor of chemical and biomolecular engineering and of materials science and nanoengineering.

The paper combines Biswal’s expertise with magnetic nanoparticles with lead author Qing Wang’s experience with amines. The amines’ role is to guide the nanoparticles to oil droplets — amines carry a positive charge and oil is negatively-charged, so they attract. Magnets are then used to draw all the nanoparticles out of the solution.

They tested the nanoparticles in emulsions produced in the lab using either model oil or crude oil. In both cases, the team dropped their compound into the emulsions, shook them by hand or machine, and had oil-nanoparticle bonds form within minutes. Some of the oil floated to the top by this stage. The test tubes were then placed atop a magnet which drew the rest to the bottom — leaving clean water in between.

The research is remarkable as nanoparticles tend to aggregate (clump together) in high-salinity environments — such as those found in reservoir fluids — but the ones developed by the team remain stable in produced water. Furthermore, these nanoparticles can be treated with a solvent to recover the oil; they can be re-used after cleaning. So far, the team proved that the nanoparticles can go through six charge-discharge cycles while remaining effective. However, they suspect that the compound can remain effective for many more cycles.

Biswal’s team is now designing a flow-through reactor to scrub large quantities of produced water and automatically recycle the nanoparticles.

Household oil pollution is a huge issue nowadays, one that the team’s efforts may help address. Oil scrubbing may help protect the waterways for communities that can’t or don’t treat wastewater, or create an extra precaution for communities that do.

Earth’s oceans generate a second, tiny, previously-unknown magnetic field, ESA satellites find

As it transits through the skies above, the Moon’s pull on the ocean’s salty depths generates a second, if much weaker, global magnetic field.

The ebb and flow of salty water, caused by our Moon’s gravitational pull, can induce their own magnetic field — one which a trio of European Space Agency’s (ESA) satellites has mapped in exquisite detail.

Known as “Swarm”, the trio of satellites was blasted off into orbit back in 2013 to help us better understand the planet’s magnetic field. Most of that field is produced by the churnings of molten iron in the Earth’s core, functioning like a massive underground dynamo. There are other secondary effects, however, such as those produced by human activity — and those are the effects Swarm was intended to peer into.

Imagine the surprise among ESA’s researchers when the satellites stumbled into a whole new magnetic phenomenon.

“It’s a really tiny magnetic field. It’s about 2-2.5 nanotesla at satellite altitude, which is about 20,000 times weaker than the Earth’s global magnetic field,” Nils Olsen, from the Technical University of Denmark, told BBC News.

What set the satellite trio apart from its peers — and enabled this discovery — is the way they ‘see’ water. Other devices we’ve sent in orbit record tides as a change in sea-surface height, but Swarm’s magnetic instruments view the movements of the entire column of water, all the way down to the seabed.

Water is diamagnetic, meaning that it has weak magnetic qualities when a magnetic field is applied to it. However, adding salt reduces its diamagnetism but makes it a good, but not great, electrical conductor — meaning it will start interacting with magnetic fields, relatively weakly. Still, oceans house humongous quantities of water, and as tides cycle around ocean basins, the overall effect is enough to ‘pull’ the geomagnetic field lines along. The interaction between saltwater and the Earth’s magnetic field also generates electrical currents, which, in turn, induce their own magnetic signals.

Studying the ebb and flow of this second magnetic field can let us peer into the movement of deep bodies of water. Oceans capture, store, and move a lot of heat around, and Swarm’s findings could help researchers build better models of Earth’s systems — particularly useful in understanding the effects of climate change.

The magnetic signature of the tides causes a “weak magnetic response” deep below the sea, Olson explained — which could allow us to peer into the electrical goings-on of our planet’s lithosphere and upper mantle. Such data will help us better map these structures, as well as the tectonic activity that drives earthquakes and volcanic eruptions.

“Since oceans absorb heat from the air, tracking how this heat is being distributed and stored, particularly at depth, is important for understanding our changing climate,” Olson said in a statement, adding that the discovery “gives us a truly global picture of how the ocean flows at all depths.”

The professor was speaking at the European Geosciences Union General Assembly (EGU) in Vienna, Austria, where a clutch of new Swarm results have been released.

New NASA data reveals many of Jupiter’s hidden secrets

A series of four papers using data from NASA’s Juno mission reveals intriguing information about Jupiter, including its gravitational field, its atmospheric flows, its interior composition and its polar cyclones.

Jupiter’s winds are tightly connected to the planet’s gravitational and magnetic fields. Image credits: NASA / ESA / UC Berkeley.

When the Juno mission was successfully launched in 2011, astronomers worldwide were thrilled. The shuttle had the potential to reveal valuable information about Jupiter and its satellites — and that potential has been thoroughly fulfilled. The new papers are the latest in a long chain of remarkable findings about the most massive planet in our solar system, adding some much-needed pieces to the puzzle.

In the first paper, researchers led by Luciano Iess of the Sapienza University of Rome in Italy used Doppler data to study Jupiter’s gravitational field. The data allowed researchers to measure Juno’s velocity down to 0.01mm/s accuracy, even while the shuttle is traveling at speeds of up to 70 km/s in orbit.

Jupiter’s gravitational field is famously asymmetrical, which is unusual for fast-rotating and oblate (squashed at the poles) gas giants. This gravitational asymmetry is caused by hydrogen-rich gas is flowing asymmetrically deep in the planet, and Juno was able to study this process.

This picture of the Jupiter’s South Pole is a mosaic of many images acquired by the Jovian InfraRed Auroral Mapper on board the Juno shuttle. The images have been taken in different times while Juno was leaving the planet after the closest approach. What you see here is the heat (measured as radiance) coming out from the planet through the clouds: yellow indicates the presence of thinner clouds and dark red the thicker ones.
Credit: NASA/SWRI/JPL/ASI/INAF/IAPS

Two other papers looked at different physical parameters of Jupiter. A team led by Yohai Kaspi of the Weizmann Institute of Science in Israel used another asymmetry, that of Jupiter’s magnetic field, to calculate the depth of Jupiter’s atmosphere, finding that the mass of the atmosphere amounts for about 1% of the planet’s total mass. Meanwhile, Tristan Guillot and co-authors report that at depths greater than 3,000 kilometers below cloud level, Jupiter’s deep interior is made up of a fluid mixture of hydrogen and helium, rotating as a solid body. They also found that the speed of the above-mentioned winds extend some 3,000 km beneath the cloud level, dropping in intensity with altitude.

Even with all this information, we’re still just barely scratching the surface of what we know about Jupiter.

“We’re at the beginning of dissecting Jupiter,” says Juno mission leader Scott Bolton of the Southwest Research Institute in San Antonio.

However, there’s also a downside to the Juno mission: it offered so much valuable data that it’s gonna be very hard to top it. In an accompanying News&Views article, planetary scientist Jonathan Fortney of the University of California Santa Cruz praised the work, writing:

“The work demonstrated here is extremely robust,” Fortney wrote in his editorial. “I do not foresee another leap in knowledge on Jupiter’s interior after the Juno mission ends, unless astronomers are able to study the planet’s internal oscillations, as has been done for the Sun.”

Fortunately, Juno will remain in orbit for at least a couple of years, so we’ll certainly have more to learn about Jupiter.

Journal References:

  1. Measurement of Jupiter’s asymmetric gravity field. Corresponding Author: Luciano Iess (Sapienza Università di Roma, Rome, Italy). DOI: 10.1038/nature25776. http://nature.com/articles/doi:10.1038/nature25776
  2. Jupiter’s atmospheric jet streams extend thousands of kilometres deep. Corresponding Author: Yohai Kaspi (Weizmann Institute of Science, Rehovot, Israel). DOI: 10.1038/nature25793. http://nature.com/articles/doi:10.1038/nature25793
  3. A suppression of differential rotation in Jupiter’s deep interior. Corresponding Author: Tristan Guillot (Université Côte d’Azur, Nice, France). DOI: 10.1038/nature25775. http://nature.com/articles/doi:10.1038/nature25775
  4. Clusters of cyclones encircling Jupiter’s poles. Corresponding Author: Alberto Adriani (INAF-Istituto di Astrofisica e Planetologia Spaziali, Rome, Italy). DOI: 10.1038/nature25491. http://nature.com/articles/doi:10.1038/nature25491

Scientists want to track ocean heat using magnetic fields

As the Earth heats up, much of the heat sinks into the oceans. But tracking that heat and understanding what it does in the depth is a complex task which has proved challenging. Now, geophysicists may have found a surprising way of doing that: using magnetic fields.

Image credits: NASA / JPL

If you’d hard press me to say one area in which we need to up our understanding on, it’s the oceans. Oceans cover the vast majority of the Earth, and yet as the saying goes – in some ways, we know more about Mars than about our oceans.

“If you’re concerned about understanding global warming, or Earth’s energy balance, a big unknown is what’s going into the ocean,” said Robert Tyler, a research scientist at Goddard. “We know the surfaces of the oceans are heating up, but we don’t have a good handle on how much heat is being stored deep in the ocean.”

The reason for this is pretty straightforward — ocean studies are difficult and expensive, especially when it comes to global warming. We can’t see the heat, we can’t really sense it, and we can’t easily study it. But it’s especially important to understand if we want to improve our projections. What Tyler is proposing has the potential to provide global ocean heat measurements, integrated over all depths, using only satellite observations.

His method cleverly lies on some properties of seawater. For starters, seawater is highly conductive. Therefore, as ocean water moves around and tides kick in, there are some very slight variations in the Earth’s magnetic lines. The ocean flow attempts to drag the field lines around, Tyler says and this can be observed. We’re talking about very small fluctuations, but they have been detected from events such as oceanic swell, eddies, tsunamis, and tides.

“The recent launch of the European Space Agency’s Swarm satellites, and their magnetic survey, is providing unprecedented observational data of the magnetic fluctuations,” Tyler said. “With this comes new opportunities.”

We have a pretty good idea of how ocean currents move around, and with the high-resolution data from the Swarm satellites, we might pick up these magnetic fluctuations. At this point, you’re probably what all this has to do with global warming. Well, here’s another fun bit: the magnetic fluctuations depend on the electrical conductivity – and the electrical conductivity relies on the temperature.

So the theory is that by studying these magnetic anomalies, we can detect the heat. But does the theory stand?

The answer is ‘yes and no’. Tyler has presented his proof of concept at the American Geophysical Union meeting, but as he himself admits, there is a lot of room for improvement in terms of how the data are processed and modeled. To my knowledge, this is the first such study and it won’t be finished overnight. But the prospects are enthralling. Float and ship measurements around Antarctica are scarce and deep water temperature measurements are a bit random. Using only satellites to study ocean temperature would be a godsend. So for now, the method shows a lot of promise, but we’re still waiting on some more peer review before we can jump on this bandwagon.

There is no ‘Nazi Train’, Polish geophysicists find

This summer in Poland, two treasure hunters discovered what they believe was a WWII Nazi train filled with treasure, in a buried tunnel. Poland’s Deputy Culture Minister Piotr Zuchowski said authorities were led to the spot and that he was 99% convinced that the treasure had been located. But according to scientists Krakow’s AGH University of Science and Technology, we shouldn’t believe the hype.

Geophysicists examining the site of the alleged train.

From the very start, there was something unclear about this story. The evidence for the 99% belief in the Nazi train was based on so-called GPR (ground penetrating radar)… except the image they published wasn’t from GPR. I’m not sure what it was from, but I’ve worked with similar equipment in recent years, and have consulted with people who have done so even more – everyone agreed that it’s not GPR. That’s when the first question marks emerged about the validity of the involved science. Now, a team of researchers from Krakow University of Science and Technology came back to look in more detail – using magnetic and gravity measurements.

While ground penetrating radar works by emitting an electromagnetic pulse and recording its return, gravity and magnetic measurements measure existing fields. Gravity is suited for detecting large structures and underground voids – as they create a high enough contrast. Meanwhile, magnetic measurements are highly susceptible to metals, so if there were a treasure or some load of guns there, you’d definitely expect to see it. Even if there was a train, it would definitely have lots of metal you would see through magnetics… except you don’t. The team from AGH University was convinced there was no Nazi train.

“There may be a tunnel,” Janusz Madej, leader of the team, said at a press conference. “But there is no train.”

This seems to translate into “we found some kind of buried structure, but there was no indication of anything metallic.” Piotr Koper and Andreas Richter, the two men who claimed to have located the train in Walbrzych, Poland, still stand by their discovery, but the science seems to claim otherwise.

“There can’t be a mistake,” Koper said Tuesday, according to the newspaper.

Investigations will likely continue in the future, and using more geophysical methods in conjunction with each other could fill in the gaps, because there is always uncertainty with any remote detection method. Drills will also be carried on to directly see what’s down there.

Between 1943 and 1945, the Nazis forced prisoners of war to dig more than 9km of tunnels near Walbrzych, probably to be used as factories. However, popular folklore believes the Nazis wanted to establish a secret command centre linked by tunnels to the Owl Mountains south-east of the city. People have been chasing the legend of the train for decades, and apparently, they’ll have to keep looking.

Understanding a unique type of magnetism

Using low-frequency laser pulses, a team of researchers has carried out the first measurements on a mineral called herbertsmithite. This (pretty awesome looking) mineral features a unique kind of magnetism.

hebertsmithe

A sample of the mineral herbertsmithite.
PHOTO: ROB LAVINSKY/IROCKS.COM

Insite it, magnetic elements constantly fluctuate, leading to an exotic magnetic state, unlike conventional magnetism in which all magnetic forces allign in the same direction and also unlike antiferromagnets, where adjacent magnetic elements align in opposite directions, practically nullifying the material’s magnetic field.

A joint team from MIT, Boston College and Harvard University has successfully carried out these measurements, revealing a signature in the optical conductivity of the spin-liquid state that reflects the influence of magnetism on the motion of electrons; the quantum spin liquid is a state that can be achieved in a system of interacting quantum spins – the term “liquid” simply refers to a disordered state of matter. This supports a number of theoretical predictions which had been made. Nuh Gedik, the Biedenharn Career Development Associate Professor of Physics at MIT and lead author of the study was thrilled:

“We think this is good evidence,” Gedik says, “and it can help to settle what has been a pretty big debate in spin-liquid research.”

Another sample, via Wikipedia.

Another sample, via Wikipedia.

Daniel Pilon, a graduate student also at MIT was also happy to be part of the first experiment which tackles this unique type of magnetism:

“Theorists have provided a number of theories on how a spin-liquid state could be formed in herbertsmithite,” Pilon explains. “But to date there has been no experiment that directly distinguishes among them. We believe that our experiment has provided the first direct evidence for the realization of one of these theoretical models in herbertsmithite.”

 

Quantum spin liquids such as this one have been proposed all the way back in 1973, but up until a few years, this was only considered to be a theoretical state. It took almost 40 years to actually discover this mineral which exhibits such a state.

These exciting discoveries will remain in the lab for now, as no forseeable direct advantage ca be drawn from this state. Still, these are only the first steps in what is a thrilling new field.

Gedik says, “Although it is hard to predict any potential applications at this stage, basic research on this unusual phase of matter could help us to solve some very complicated problems in physics, particularly high-temperature superconductivity, which might eventually lead to important applications.” In addition, Pilon says, “This work might also be useful for the development of quantum computing.”

Physicists create artificial magnetic monopoles

A team of researchers from Cologne, Munich and Dresden have managed to create artificial magnetic monopoles, similar in many ways to a fundamental particle postulated by Paul Dirac in 1931.

Monopoles and Dipoles

Until now, a magnetic monopole, the magnetic analogue to an electric charge has never been observed – all we had until now were dipoles: magnetic bodies which have two poles, noted as North and South. Basically, a dipole is a pair of electric charges or magnetic poles, of equal magnitude but of opposite sign or polarity, separated by a small distance. A monopole, as you probably guessed by now – is just a single pole.

A magnetic monopole is a hypothetical particle in particle physics that is an isolated magnet with only one magnetic pole. The interest with monopole particles stems mostly from particle theories (like superstring theory, for example), but in recent times, there’s been industrial interest too, as several companies are interested in using magnetic whirls in the production of computer components.

Creating a monopole

Credit: Ch. Schütte/University of Cologne

Credit: Ch. Schütte/University of Cologne

To do this, researchers merged tiny magnetic whirls, so-called skyrmions – hypothetical particles which have been described, but not conclussively proven. At the point of merging, the physicists were able to create a monopole, which has similar characteristics to a fundamental particle postulated by Paul Dirac in 1931 to explain why electrons and protons carry particles of the exact same value.

The thing is, since this doesn’t have two poles, it doesn’t create a magnetic field per se, but even so, it is possible to measure them experimentally in the same manner as normal magnet fields: by the measure in which they deflect electrons.

“It is fascinating that something as fundamental as a magnetic monopole can be realized in a piece of material,” describes Stefan Buhrandt. Despite this, artificial monopoles cannot solve Dirac’s problem: only electrons in solid state, but not protons, feel the artificial magnet fields.

Sadly, NASA has to debunk Mayan apocalypse conspiracies again

It saddens me to see NASA having to come out again and explain why the whole ‘Mayan end of the calendar apocalypse’ thing; the US space agency came out with on Saturday in an attempt to debunk these claims and downplay concerns that the world will end in 2012.

Mr Don Yeomans from NASA explains that all these concerns rely on nothing more than conspiracy theories, noting that even the way the Mayan calendar was interpreted is wrong.

“Their calendar does not end on December 21, 2012; it’s just the end of the cycle and the beginning of a new one. It’s just like on December 31, our calendar comes to an end, but a new calendar begins on January 1,” said Mr. Yeomans.

He then continued, addressing a number of scenarios devised by adepts of these ‘theories’, including collision with a hidden giant planet, termed Nibiru or Planet X by believers. They claim that the planet is on a collision course with Earth and that it is currently out of the reach of average astronomers, and main space agencies are working in secret to avoid spreading the panic.

“There are no planetary alignments in the next few decades, Earth will not cross the galactic plane in 2012, and even if these alignments were to occur, their effects on the Earth would be negligible. Each December the Earth and sun align with the approximate center of the Milky Way Galaxy but that is an annual event of no consequence,” says the U.S. space agency.

Mr Yeomans then addresses another fear – that of a solar flare. While he explains that our planet will face solar storms this year, this is a result of the fact that the Sun is nearing the peak of its 11 year cycle – a peak which will actually occur in May 2013, not December 2012. Also, there is absolutely no indication of a truly massive solar storm in the near future.

They even spoke about one of the cookiest ideas I’ve ever heard: reconfiguration in the alignment of the Earth’s magnetic poles that could severely affect human activities on the planet; while magnetic poles do switch places, this process happens every 750.000 years, and the process itself lasts a few millenia.

“A reversal in the rotation of Earth is impossible. There are slow movements of the continents (for example Antarctica was near the equator hundreds of millions of years ago), but that is irrelevant to claims of reversal of the rotational poles,” says the space agency. “As far as we know, such a magnetic reversal doesn’t cause any harm to life on Earth. A magnetic reversal is very unlikely to happen in the next few millennia, anyway.”

Then again, there’s always the classical asteroid fear.

“The Earth has always been subject to impacts by comets and asteroids, although big hits are very rare. The last big impact was 65 million years ago, and that led to the extinction of the dinosaurs. Today NASA astronomers are carrying out a survey called the Spaceguard Survey to find any large near-Earth asteroids long before they hit,” say scientists.

So people, please calm down and be logical for a moment; all these conspiracy theories were blown out of proportions by Hollywood-like schemes and do absolutely nothing but plant irrational fear. It’s not the first time researchers from NASA and not only come out and speak against such claims, but hopefully, people will actually get it this time.

Part of Earth’s mantle is shown to be conductive under high pressures and temperatures

Ever since researchers started studying the Earth’s spin, they noticed that the spin isn’t perfect. Many believe this is a result of the different elements in the Earth’s core, mantle and crust, which have different densities and generate different friction.

Most researchers studying this wobble agreed that the mantle would have to respond to the magnetic tug of the core – but the problem here is that the mantle is made out of rocks, and not only metals, like the core, and therefore shouldn’t be conductive; hence, quite a predicament. However, new research done by Kenji Ohta and his colleagues at Osaka University in Japan.

As they describe in their paper published in Physical Review Letters, it appears that a mineral called Wustite (FeO), believed to be a significant component of the Earth’s mantle, can be made to conduct electricity at high temperatures and pressures.

In order to test their theory, they raised the mineral up to 1600°C and applying 70 gigapascals of pressure, and they found it becomes just as conductive as an average metal. To find out what happens in even harsher conditions, they heated the mineral to 2200°C and doubled the pressure – finding the same results, suggesting that the same thing would happen even deeper in the mantle, closer to the core-mantle boundary.

In order to better understand why this particular mixture of Oxygen and iron becomes conductive at high pressures, the team did density and electrical conductivity tests and their results seem to suggest that this metallization is related to the spin crossover.

Defect in graphene opens up even more possibilities

Graphene is probably the ‘substance of the century’, and it will probably be for us what plastics were in the 1900s. Now, a flower-like defect in the material that can occur during the fabrication process could have a significant effect on graphene’s already impressive mechanical, magnetic, and electrical properties.

Amazing graphene

Graphene is practically a one atom thick layer of carbon atoms, densely packed in a hexagonal (honey comb) lattice. The carbon-carbon bond length in graphene is about 0.142 nanometers. It is already known that it has unbelievable strength and conductivity, both of which are a result of its structure.

Graphene differs from conventional 3D materials in that it is a semi-metal or zero-gap semiconductor. It has a remarkable electron mobility at room temperature and it has been showed that electrical current going through it can magnetize it.

Seven deffects

A team of researchers from the National Institute of Standards and Technology (NIST) and Georgia Tech described for the first time a class of seven defects that can occur during its fabrication. Basically, these defects appear as a result of the movement of the carbon atoms at high temperatures when producing graphene by heating silicon carbide under ultrahigh vacuum. The rearrangements which require the least energy from graphene are switching from six-member carbon rings to rings containing five or seven atoms, which keeps all the carbon atoms happy with no unsatisfied bonds. However, these changes create a new type of defect or grain boundary loop in the honeycomb lattice. According to researchers, the fabrication process plays a huge role in this structural malfunction.

“As the graphene forms under high heat, sections of the lattice can come loose and rotate,” says NIST researcher Eric Cockayne . “As the graphene cools, these rotated sections link back up with the lattice, but in an irregular way. It’s almost as if patches of the graphene were cut out with scissors, turned clockwise, and made to fit back into the same place, only it really doesn’t fit, which is why we get these flowers.”

The incredibly lattice is already stronger than steel, but it is also extremely rigit; these (technically speaking) defects might do it a world of good, giving it much needed flexibility, thus making it even more resistant to fractures or tears. Further research will provide some new insight as to how these flower-like structures can be eliminated or created at will, depending on the needs. Furthermore, these seven new structures would each have different not only mechanical, but also electrical and magnetic properties. All hail graphene !

New spin makes graphene magnetic

I was telling you a while ago about the revolutionary material called graphene. Graphene is a one atom thick layer of carbon packed in a honeycomb lattice. Now, a team led by Professor Andre Geim, recipient of the Nobel Prize for graphene, showed that electric current (which is basically a flow of electrons) can magnetise the material.

This could lead to an extremely fast development of spintronics, an emerging group of technologies that exploit the intrinsic spin of the electron, in addition to its fundamental electric charge that is exploited in microelectronics. The findings involve a great number of researchers from the US, Russia, Japan and the Netherlands.

It is believed that in future spintronics transistors and devices, coupling between the current and spin will be direct, without having to use magnetic materials to inject spins, which is the way things are done at the moment.

Professor Geim said:

“The holy grail of spintronics is the conversion of electricity into magnetism or vice versa. We offer a new mechanism, thanks to unique properties of graphene. I imagine that many venues of spintronics can benefit from this finding.”

Antonio Castro Neto, a physics professor from Boston who wrote a news article for the Science magazine which accompanies the research paper commented: “Graphene is opening doors for many new technologies.

“Not surprisingly, the 2010 Nobel Physics prize was awarded to Andre Geim and Kostya Novoselov for their groundbreaking experiments in this material. Apparently not satisfied with what they have accomplished so far, Geim and his collaborators have now demonstrated another completely unexpected effect that involves quantum mechanics at ambient conditions. This discovery opens a new chapter to the short but rich history of graphene.”

Geophysics shows plume of Yellowstone volcano is much larger than previously believed

Yellowstone is without a doubt one of the most fascinating places on the face of the planet. But it doesn’t only attract families or people who want to relax, but it attracts scientists as well, and among them, geologists and geophysicists hold a top spot. University of Utah researchers made the first large-scale picture of the electrical conductivity of the enormous underground plume of hot and partially molten rock that feeds the Yellowstone volcano. The image suggests that it is much bigger than previously thought before, when it was also investigated with geophysical methods, but in the form of seismic waves.

“It’s like comparing ultrasound and MRI in the human body; they are different imaging technologies,” says geophysics Professor Michael Zhdanov, principal author of the new study and an expert on measuring electric and magnetic fields, with the purpose of investigating underground objectives.

In a previous 2009 study, researchers (Smith) used seismic waves from earthquakes to make an accurate image of the plume that feeds the volcano. In addition to other factors, seismic waves travel faster in cold rocks and slower in hotter rocks, so seismic velocity information can be used to make a pretty accurate 3D picture, much like X-rays are combined to make a medical CT scan.

But in this type of cases, electric measurements can be much more direct and offer much more answers, but they measure slightly different things. Seismic analysis shows which rocks are hotter and slow down waves, while electric measurements show the conductivity of the rocks, and is especially sensible to briny fluids that conduct electricity.

“It [the plume] is very conductive compared with the rock around it,” Zhdanov says. “It’s close to seawater in conductivity.”

The new study doesn’t say anything about the chances of a catastrophic eruption at Yellowstone, but it does seem to suggest than when it is going to come, it will be bigger than previously expected.

A solar tsunami set to generate celestial show tonight

A huge plasma eruption that took place on the Sun has caused a “solar tsunami” of ionized atoms that are on a course for our planet on Tuesday night. Nothing to be too alarmed here, except for the disruption of some satellites.

It will however generate quite a show, a rare and unpredictable one too.

“It’s the first major Earth-directed eruption in quite some time,” Leon Golub of the Harvard-Smithsonian Center for Astrophysics told Space.com

NASA’s Solar Dynamics Observatory was launched in February, with the goal of looking into the Sun and figuring out how phenomena such as this work. The best show will be in North America, and it could also trigger some aurorae, which will make it even more awesome. Be sure to keep an eye on the sky tonight.