ESA Swarm's precise sense of magnetism - Video

Data from Swarm were used to generate a model of the magnetic field from Earth’s lithosphere. 

The image compares the Swarm model with the 'Chaos-4' model and shows good agreement, especially considering Swarm is still only in the calibration and validation phase of the mission. 

The colours in the image show differences between the two models. 

Credit: ESA/DTU Space–N. Olsen

Although they were launched only five months ago, ESA's trio of Swarm satellites are already delivering results with a precision that took earlier missions 10 years to achieve.

Engineers have spent the last five months commissioning the identical satellites and carefully guiding them into their orbits to provide the crucial measurements that will unravel the mysteries of Earth's magnetic field.

Swarm has a challenging task ahead.

Together, the satellites will measure and untangle the different magnetic readings that stem from Earth's core, mantle, crust, oceans, ionosphere and magnetosphere.

In addition, information will also be provided to calculate the electric field near each satellite – an important counterpart to the magnetic field for studying the upper atmosphere.

Two satellites are now orbiting almost side by side and have started their operational life at 462 km altitude. The third is higher, at 510 km.

The readings made at different locations will be used to distinguish between the changes in the magnetic field caused by the Sun's activity and those signals that originate from inside Earth.

Swarm is now in its fine-tuning phase but it has already produced enough information to build models of the magnetic field for comparison with existing models.


Swarm is ESA’s first constellation of Earth observation satellites. The three identical satellites are designed to measure precisely the magnetic signals that stem from Earth’s core, mantle, crust and oceans, as well as its ionosphere and magnetosphere. 

Carrying a host of sophisticated instruments, the constellation is key to measuring and separating the different sources of magnetism and to making models in unprecedented detail and accuracy. 

The fact that Swarm is a constellation also means that, for the first time, mantle conductivity can be mapped in 3D from space. 

The satellites also offer a new way of studying the effect that solar particles have close to Earth. 

Credit: ESA/AOES Medialab

This proves that only a few months of Swarm data agree very well with a decade or more of predecessor missions.

For example, the image above shows the differences between Swarm's version of the magnetic field from Earth's crust compared to the 'Chaos-4' model.

There are very few differences, demonstrating that the mission is working well.

ESA's mission manager, Rune Floberghagen, said, "Although it has certainly been a big job getting the three satellites ready for operations, we are all very happy with how well the mission is doing so soon after launch.

"Scientists will start to have access to the mission's magnetic field data in a couple of weeks."

Earth's magnetic field: The magnetic field and electric currents near Earth generate complex forces that have immeasurable impact on our everyday lives.

Although we know that the magnetic field originates from several sources, exactly how it is generated and why it changes is not yet fully understood.

ESA’s Swarm mission will help untangle the complexities of the field. 

Credit: ESA/ATG Medialab

Over the coming years, this innovative mission will provide new insight into many natural processes, from those occurring deep inside the planet to weather in space caused by solar activity.

In turn, this information will yield a better understanding of why the magnetic field is weakening.

The first results and status of the mission will be presented at a Swarm science meeting on 19–20 June in Denmark.

NASA's Spitzer Space Telescope: Planet-forming Disks Explained by Magnetism

Magnetic loops carry gas and dust above disks of planet-forming material circling stars, as shown in this artist's conception.

Image Credit: NASA/JPL-Caltech

Astronomers say that magnetic storms in the gas orbiting young stars may explain a mystery that has persisted since before 2006.

Researchers using NASA's Spitzer Space Telescope to study developing stars have had a hard time figuring out why the stars give off more infrared light than expected.

The planet-forming disks that circle the young stars are heated by starlight and glow with infrared light, but Spitzer detected additional infrared light coming from an unknown source.

A new theory, based on three-dimensional models of planet-forming disks, suggests the answer: Gas and dust suspended above the disks on gigantic magnetic loops like those seen on the sun absorb the starlight and glow with infrared light.

Neal Turner

"If you could somehow stand on one of these planet-forming disks and look at the star in the center through the disk atmosphere, you would see what looks like a sunset," said Neal Turner of NASA's Jet Propulsion Laboratory, Pasadena, Calif.

The new models better describe how planet-forming material around stars is stirred up, making its way into future planets, asteroids and comets.

While the idea of magnetic atmospheres on planet-forming disks is not new, this is the first time they have been linked to the mystery of the observed excess infrared light.

According to Turner and colleagues, the magnetic atmospheres are similar to what takes place on the surface of our sun, where moving magnetic field lines spur tremendous solar prominences to flare up in big loops.

Stars are born out of collapsing pockets in enormous clouds of gas and dust, rotating as they shrink down under the pull of gravity.

As a star grows in size, more material rains down toward it from the cloud, and the rotation flattens this material out into a turbulent disk. Ultimately, planets clump together out of the disk material.

In the 1980s, the Infrared Astronomical Satellite mission, a joint project that included NASA, began finding more infrared light than expected around young stars.

Using data from other telescopes, astronomers pieced together the presence of dusty disks of planet-forming material but eventually it became clear the disks alone weren't enough to account for the extra infrared light, especially in the case of stars a few times the mass of the sun.

One theory introduced the idea that instead of a disk, the stars were surrounded by a giant dusty halo, which intercepted the star's visible light and re-radiated it at infrared wavelengths.

Then, recent observations from ground-based telescopes suggested that both a disk and a halo were needed.

Finally, three-dimensional computer modeling of the turbulence in the disks showed the disks ought to have fuzzy surfaces, with layers of low-density gas supported by magnetic fields, similar to the way solar prominences are supported by the sun's magnetic field.

The new work brings these pieces together by calculating how the starlight falls across the disk and its fuzzy atmosphere.

The result is that the atmosphere absorbs and re-radiates enough to account for all the extra infrared light.

Mercury meteorite among world's rarest rocks

The magnetism of the meteorite formally known as NWA 7325 exactly matches that of Mercury.

Talk about a precious stone—the largest piece of the only known meteorite from the planet Mercury has found its way to Yale, where it is now on display at the Peabody Museum of Natural History.

Known as NWA 7325, the fist-size, greenish space rock is a rarity among rarities: there just aren't many verified planetary meteorites.

Scientists know of about 70 from Mars and, until now, none from any of the other planets in Earth's solar system.

There are about 180 known meteorites from the moon. NWA 7325 is the first believed to be from Mercury.

"If it's not from Mercury, it's from a very interesting place," said Anthony J. Irving, an expert in planetary meteorites at the University of Washington, during a recent appearance at the Peabody.

The meteorite's chemical composition provides the strongest evidence that it came from Mercury, a rocky world that is the smallest planet in Earth's solar system and closest to the sun, Irving said.

He noted the object's high magnesium and chromium content and its low iron content are similar to those of Mercury. Also, the meteorite's magnetism matches Mercury's magnetism exactly, he said.

The NWA in the name stands for Northwest Africa. The meteorite was found in fragments in 2012 in the Moroccan desert.

It is estimated to be 4.56 billion years old, about the age of Earth. The piece on display at the Peabody was sold to a private collector in Germany, Stefan Ralew, who consulted with Irving.

The exhibition, "From Mercury to Earth? A Meteorite Like No Other," runs Nov. 22 to Sept. 2, 2014.

Dark Matter: Can Simple Anapole theory explain it?

This is a comparison of an anapole field with common electric and magnetic dipoles. The anapole field, top, is generated by a toroidal electrical current. 

As a result, the field is confined within the torus, instead of spreading out like the fields generated by conventional electric and magnetic dipoles. 

Credit: Michael Smeltzer, Vanderbilt University

Most of the matter in the universe may be made out of particles that possess an unusual, donut-shaped electromagnetic field called an anapole.

This proposal, which endows dark matter particles with a rare form of electromagnetism, has been strengthened by a detailed analysis performed by a pair of theoretical physicists at Vanderbilt University: Professor Robert Scherrer and post-doctoral fellow Chiu Man Ho.

An article about the research was published online last month by the journal Physics Letters B.

"There are a great many different theories about the nature of dark matter. What I like about this theory is its simplicity, uniqueness and the fact that it can be tested," said Scherrer.

Robert Scherrer

In the article, titled "Anapole Dark Matter," the physicists propose that dark matter, an invisible form of matter that makes up 85 percent of the all the matter in the universe, may be made out of a type of basic particle called the Majorana fermion.

The particle's existence was predicted in the 1930's but has stubbornly resisted detection.

A number of physicists have suggested that dark matter is made from Majorana particles, but Scherrer and Ho have performed detailed calculations that demonstrate that these particles are uniquely suited to possess a rare, doughnut-shaped type of electromagnetic field called an anapole.

This field gives them properties that differ from those of particles that possess the more common fields possessing two poles (north and south, positive and negative) and explains why they are so difficult to detect.

"Most models for dark matter assume that it interacts through exotic forces that we do not encounter in everyday life. Anapole dark matter makes use of ordinary electromagnetism that you learned about in school – the same force that makes magnets stick to your refrigerator or makes a balloon rubbed on your hair stick to the ceiling," said Scherrer.

"Further, the model makes very specific predictions about the rate at which it should show up in the vast dark matter detectors that are buried underground all over the world. These predictions show that soon the existence of anapole dark matter should either be discovered or ruled out by these experiments."

More information: Anapole dark matter. Physics Letters B, 2013; 722 (4-5): 341 DOI: 10.1016/j.physletb.2013.04.039 ( adsabs.harvard.edu/abs/2013PhLB..722..341)

Laser first: Solves the puzzle of how the Universe got its magnetism

Scientists have demonstrated for the very first time how a laser can be used to stimulate the formation of magnetic fields, similar to those thought to be involved in the formation of the very first galaxies.

The findings published in Nature (26 January 2012) could help solve the riddle of how the Universe originally got its magnetism.

Magnetic fields exist throughout galactic and intergalactic space and in the stars and planets.

The magnetic fields in our solar system are important, since they shield us from the harmful effects of cosmic rays allowing life to thrive.

What is puzzling is how they were originally created. A way of creating magnetic fields without a magnet has long been theorised, but never before has the process been demonstrated.

A team, led by Oxford University physicists, have used a high-power laser to explode a rod of carbon, similar to pencil lead, in helium gas.

The explosion was designed to mimic the cauldron of plasma – an ionized gas containing free electrons and positive ions – out of which the first galaxies formed.

It was designed to prove a theory, known as the ‘Biermann battery effect’ that demonstrated how magnetic fields could form where none had existed before.

The team found that within a microsecond of the explosion strong electron currents and magnetic fields formed around a shock wave.

Scientists including Bob Bingham and Alex Robinson at the Central Laser Facility at STFC’s Rutherford Appleton laboratory took these results and compared them to existing planetary data.

Using computational resources from STFC’s e-science department, they scaled them through 22 orders-of-magnitude.

They found that their measurements closely matched theories which predict that tiny magnetic fields - ‘magnetic seeds’ – precede the formation of galaxies.

These fields can be amplified by turbulent motions and can strongly affect the evolution of the galactic medium.

Professor Bingham said: “The advantage of using lasers to simulate the early processes in the formation of magnetic fields is that you can create, with a burst of laser light just a billionth of a second long, an effect that in space would take years to develop on an incomprehensible scale”.

Dr Gianluca Gregori from Oxford University, who led the work said: “Our experiment recreates what was happening in the early Universe and shows how galactic magnetic fields might have first appeared.

It opens up the exciting prospect that we will be able to explore the physics of the cosmos, stretching back billions of years, in a laser laboratory here on Earth”.

The experiments were conducted at the Laboratoire pour l’Utilisation de Lasers Intenses laser facility in France.

For further details see the Oxford University press release

Richard Feynman Video: Explaining Magnets

Legendary physicist Richard Feynman talks about why it is so hard to answer certain science questions in layman terms

Doctor Feynman was one of the defining physicists of our time. He is commonly said to have made complex physics accessible to all, and his lectures were later published in a series of books such as “Six Easy Pieces” and “Six Not So Easy Pieces“.

He was often referred to as the “Great Explainer”, leading the BBC to produce a short series with him known as “Fun To Imagine” on key scientific concepts in the early 80s, such as this video. In fact, his lectures at the California Institute of Technology were so renowned that fellow academics, teachers and professors would often sit in to refresh their memory on important physical concepts.

Sadly, Richard Feynman passed away on 15 February 1988, but his legacy still remains.

One-Dimensional Window On Superconductivity And Magnetism

A Rice University-led team of physicists is reporting the first success in a three-year effort to build a precision simulator for superconductors using a grid of intersecting laser beams and ultracold atomic gas.
The research appears this week in the journal Nature. Using lithium atoms cooled to within a few billionths of a degree of absolute zero and loaded into optical tubes, the researchers created a precise analog of a one-dimensional superconducting wire.

Because the atoms in the experiment are so cold, they behave according to the same quantum mechanical rules that dictate how electrons behave. That means the lithium atoms can serve as stand-ins for electrons, and by trapping and holding the lithium atoms in beams of light, researchers can observe how electrons would behave in particular types of superconductors and other materials.

"We can tune the spacing and interactions among these ultracold atoms with great precision, so much so that using the atoms to emulate exotic materials like superconductors can teach us some things we couldn't learn by studying the superconductors themselves," said study co-author Randy Hulet, a Rice physicist who's leading a team of physicists at Rice and six other universities under the Defense Advanced Research Projects Agency's (DARPA) Optical Lattice Emulator (OLE) program.

In the Nature study, Hulet, Cornell University physicist Erich Mueller, Rice graduate students and postdoctoral researchers Yean-an Liao, Sophie Rittner, Tobias Paprotta, Wenhui Li and Gutherie Partridge and Cornell graduate student Stefan Baur created an emulator that allowed them to simultaneously examine superconductivity and magnetism - phenomena that do not generally coexist.

The Power of Neodymium Magnetism

Take a look at MagnetNerd.com it is full of amazing information and experiments involving Neodymium Magnetism.

Neodymium Magnets are just amazing. It's incredible how something so small can have such strong magnetic forces.