Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Iron 'snow' helps maintain Mercury's magnetic field

New scientific evidence suggests that deep inside the planet Mercury, iron “snow” forms and falls toward the center of the planet, much like snowflakes form in Earth’s atmosphere and fall to the ground.

The movement of this iron snow could be responsible for Mercury’s mysterious magnetic field, say researchers from the University of Illinois and Case Western Reserve University. In a paper published in the April issue of the journal Geophysical Research Letters, the scientists describe laboratory measurements and models that mimic conditions believed to exist within Mercury’s core.

“Mercury’s snowing core opens up new scenarios where convection may originate and generate global magnetic fields,” said U. of I. geology professor Jie (Jackie) Li. “Our findings have direct implications for understanding the nature and evolution of Mercury’s core, and those of other planets and moons.”

Mercury is the innermost planet in our solar system and, other than Earth, the only terrestrial planet that possesses a global magnetic field. Discovered in the 1970s by NASA’s Mariner 10 spacecraft, Mercury’s magnetic field is about 100 times weaker than Earth’s. Most models cannot account for such a weak magnetic field.

Made mostly of iron, Mercury’s core is also thought to contain sulfur, which lowers the melting point of iron and plays an important role in producing the planet’s magnetic field.

“Recent Earth-based radar measurements of Mercury’s rotation revealed a slight rocking motion that implied the planet’s core is at least partially molten,” said Illinois graduate student Bin Chen, the paper’s lead author. “But, in the absence of seismological data from the planet, we know very little about its core.”

To better understand the physical state of Mercury’s core, the researchers used a multi-anvil apparatus to study the melting behavior of an iron-sulfur mixture at high pressures and high temperatures.

In each experiment, an iron-sulfur sample was compressed to a specific pressure and heated to a specific temperature. The sample was then quenched, cut in two, and analyzed with a scanning electron microscope and an electron probe microanalyzer.

“Rapid quenching preserves the sample’s texture, which reveals the separation of the solid and liquid phases, and the sulfur content in each phase,” Chen said. “Based on our experimental results, we can infer what is going on in Mercury’s core.”

As the molten, iron-sulfur mixture in the outer core slowly cools, iron atoms condense into cubic “flakes” that fall toward the planet’s center, Chen said. As the iron snow sinks and the lighter, sulfur-rich liquid rises, convection currents are created that power the dynamo and produce the planet’s weak magnetic field.

Mercury’s core is most likely precipitating iron snow in two distinct zones, the researchers report. This double-snow state may be unique among the terrestrial planets and terrestrial-like moons in our solar system.

“Our findings provide a new context into which forthcoming observational data from NASA’s MESSENGER spacecraft can be placed,” Li said. “We can now connect the physical state of our innermost planet with the formation and evolution of terrestrial planets in general.”

James E. Kloeppel | EurekAlert!
Further information:

More articles from Earth Sciences:

nachricht Ice shelf vibrations cause unusual waves in Antarctic atmosphere
25.10.2016 | American Geophysical Union

nachricht Enormous dome in central Andes driven by huge magma body beneath it
25.10.2016 | University of California - Santa Cruz

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>