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Space Exploration

Why Mars’ Magnetic Field Was Lopsided: Evidence from InSight & Surveyor

By Jonathan Bala April 20, 2025

Why Mars’ Magnetic Field Was Lopsided: Evidence from InSight & Surveyor

Mars once sported a global magnetic field like Earth’s, but evidence shows that field was uneven, favoring the southern hemisphere. New simulations suggest that a fully liquid core combined with a slight temperature difference between the planet’s halves created a one‑sided dynamo. This model matches data from NASA’s InSight mission and Mars Global Surveyor, and it may reshape our understanding of how Mars lost its atmosphere and its habitability over time.

Summary

Mars today has no global magnetic field, but crustal rocks retain a southern‑hemisphere imprint.
Data from NASA’s InSight lander show Mars’ core may be fully molten, not a solid inner core and molten outer core like Earth’s.
The UT Austin study used supercomputer simulations to test a liquid‑core Mars model.
Simulations with a slight northern–southern temperature contrast drove heat outflow mainly in the south.
Heat focussed in the south powered a hemispheric dynamo, matching magnetic rock patterns.
This implies Mars’ field was never global, raising the possibility that atmospheric loss began earlier.
Future work will re‑examine InSight seismic data and refine interior models.

Introduction

Today, Mars lacks a planet‑wide magnetosphere. Yet, crustal rocks betray an ancient magnetic imprint, especially in the southern highlands. Recent data from NASA’s InSight lander indicate that Mars’ core contains more light elements than expected, lowering its melting point and suggesting it remains fully molten today. A new paper by Chi Yan and colleagues at the University of Texas Institute for Geophysics proposes that this liquid core drove a lopsided magnetic field early in Martian history.

The Mystery of a One‑Sided Field

Magnetic mapping from the Mars Global Surveyor mission first revealed a stark difference: the southern hemisphere retains strong magnetic signals, while the north is nearly barren. Scientists once thought massive impacts erased northern magnetism, but growing evidence points to a core‑driven cause. Studies show Mars lost its global field around 3.9 billion years ago, coinciding with the cooling of its core.

Molten Core and Hemispheric Heat Flow

Most models assumed Mars had a solid inner core like Earth’s. However, InSight’s seismic findings suggest a core rich in sulfur and oxygen, which delays solidification and could keep the entire core molten. Motivated by this, the UTIG team ran computer simulations on a supercomputer, varying core and mantle properties to see how a fully liquid core would behave.

Insights from Computer Models

The simulations imposed a slight temperature difference between hemispheres, with the northern mantle warmer than the south. Heat escaped preferentially through the cooler southern crust, creating vigorous fluid motion in the overlying core that powered a magnetic dynamo only in that half of the planet. The result closely matches the magnetic imprint we see today.

“The logic here is that with no solid inner core, it’s much easier to produce hemispheric magnetic fields,” said Chi Yan. jsg.utexas.edu

This model suggests Mars never had a true global shield; instead, its magnetic protection was always patchy.

Implications for Mars and Beyond

A planet’s magnetic field shields its atmosphere from solar wind. Mars’ uneven field may have allowed atmospheric stripping to begin long before the field disappeared entirely. This could mean climate change on early Mars was more severe and earlier than thought. Understanding this process helps us compare Mars to other bodies like Mercury and some icy moons, which also show odd magnetic features.

Future Directions

The authors recommend revisiting InSight’s seismic data for deeper insights into core composition. Improved models that explore a wider range of internal and external conditions may refine our picture of Mars’ dynamo history. Meanwhile, meteorite studies could provide further evidence of Mars’ magnetic past.

Table 1: Core Structure Comparison

Feature	Earth	Mars (Ancient Model)
Inner Core State	Solid iron–nickel	Fully liquid
Outer Core	Molten iron	Molten iron–light elements
Dynamo Mechanism	Full‐sphere convective flow	Hemispheric convective flow
Shield Coverage	Global magnetic field	Southern hemisphere only

Table 2: Hemispheric Magnetic Field Characteristics

Hemisphere	Magnetic Imprint	Surface Terrain
Northern	Weak	Lowlands, smooth plains
Southern	Strong	Highlands, rugged crust

Facts

Mars Global Surveyor orbited Mars from 1997 to 2006, mapping its magnetic field in detail.
InSight’s seismic measurements began in 2018, giving new clues to Mars’ interior.
Mercury also shows a global field, but weaker and offset from its center.
Martian meteorites on Earth carry tiny magnetic signatures that record ancient field strength.

References

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Geography

Hidden Structures Detected Inside Earth’s Core: What We Know So Far

By Jonathan Bala January 12, 2025

Hidden Structures Detected Inside Earth’s Core: What We Know So Far

Most of us do not think much about the ground beneath our feet. But it is more than just dirt or rocks. The ground has complicated layers. These layers are similar to the pages of a book. They hold Earth’s history. They also hold our history.

“Traditionally we’ve been taught the Earth has four main layers: the crust, the mantle, the outer core, and the inner core,” explained Australian National University geophysicist Joanne Stephenson in 2021. However, recent research suggests there is more to this story—Earth’s inner core may hold an even deeper secret.

Scientists have uncovered evidence that Earth’s inner core may consist of two distinct layers, challenging conventional models of Earth’s internal structure. By analyzing seismic waves and modeling their behavior, researchers have suggested that the iron crystals in the inner core have varying alignments. This discovery could rewrite our understanding of Earth’s formation and history.

Summary

Earth is composed of four main layers: crust, mantle, outer core, and inner core.
Research by geophysicists suggests the inner core may have two distinct layers.
The study analyzed seismic waves traveling through Earth’s layers to uncover these findings.
Differences in seismic wave speeds suggest variations in the core’s material structure.
The inner core, composed mainly of iron, may have different crystal alignments in its deepest region.
This discovery indicates the possibility of two distinct cooling events in Earth’s history.
Previous studies hinted at this innermost core, but definitive evidence was lacking until recently.
Global seismic data, including earthquake records, were used in the study.
Researchers note data gaps, particularly at polar antipodes, limit the accuracy of their findings.
Future studies aim to refine these observations and explore the implications for Earth’s history.
This discovery challenges current textbooks and models of Earth’s interior.
It adds a piece to the puzzle of Earth’s formation and the dynamics of its internal processes.

Hidden Structures Detected Inside Earth’s Core What We Know So Far — The inner core of Earth might have two separate layers. It is the center part of our planet. Scientists sometimes refer to these core layers when studying Earth’s structure.

Understanding Earth’s Layers

Traditionally, Earth’s structure has been divided into four layers:

1. Crust: The outermost layer, where we live, composed of solid rock.
2. Mantle: A thick layer of semi-solid rock that moves slowly over time.
3. Outer Core: A liquid layer composed mainly of molten iron and nickel.
4. Inner Core: A solid sphere made primarily of iron, surrounded by the outer core.

However, this model may now need revision. Seismic waves, generated by earthquakes, have provided the primary tool for understanding Earth’s internal structure. These waves travel at different speeds depending on the material they pass through, revealing critical insights about the composition and properties of Earth’s layers.

A Closer Look at the Inner Core

The inner core, long thought to be a homogenous solid layer, has been a subject of fascination for geologists and geophysicists. Recent studies have shown that this layer might not be as uniform as previously believed. Instead, it may have two distinct sub-layers with varying properties.

This groundbreaking research was led by Joanne Stephenson and her team at the Australian National University, using data collected by the International Seismological Centre. The team analyzed seismic waves traveling through the inner core and found evidence suggesting a change in the structure of iron crystals.

Evidence of a Hidden Layer

By examining the anisotropy of seismic waves—how their speed changes depending on direction—the researchers discovered differences in the core’s composition.

Some models suggest seismic waves travel faster parallel to Earth’s rotational axis.
Others propose a distinct angle of 54 degrees where slower wave speeds occur, hinting at differences in material properties.

These findings align with earlier studies but provide more robust evidence for the presence of a hidden layer within the inner core.

“We found evidence that may indicate a change in the structure of iron, which suggests perhaps two separate cooling events in Earth’s history,” Stephenson noted in her paper. “The details of this big event are still a bit of a mystery, but we’ve added another piece of the puzzle when it comes to our knowledge of the Earth’s inner core.”

Implications for Earth’s History

This discovery has profound implications for our understanding of Earth’s history and its dynamic processes.

Cooling Events:
The presence of a second layer within the inner core suggests two distinct cooling events in Earth’s past. These events may have shaped the planet’s magnetic field and its ability to sustain life.
Iron Crystal Alignment:
Variations in iron crystal alignments within the core could explain inconsistencies in seismic data and provide clues about the Earth’s formation.
Revising Models:
Current models of Earth’s internal structure may need to be revised to incorporate these findings, leading to a deeper understanding of planetary dynamics.

Table 1: Key Differences Between Earth’s Inner Core Layers

Property	Traditional Inner Core	New Hidden Layer (Innermost Core)
Composition	Solid iron-nickel	Differing iron crystal alignments
Seismic Wave Anisotropy	Parallel to equator	Parallel to rotational axis
Discovery	Long known	Recent findings by seismic studies

Challenges in Studying the Core

Despite these groundbreaking discoveries, significant challenges remain in studying Earth’s inner core.

Data Limitations

The researchers noted gaps in seismic data, particularly at polar antipodes, which limit the certainty of their conclusions. Improved seismic networks and better data collection techniques will be essential for refining these findings.

Future Research

Future studies aim to:

Fill in data gaps and improve the accuracy of seismic models.
Explore the implications of the innermost core for Earth’s magnetic field.
Investigate how these findings relate to other planetary bodies with similar structures.

Table 2: Tools for Studying Earth’s Core

Method	Description	Example Application
Seismic Waves	Analyze wave speeds and directions to infer material properties	Understanding anisotropy in the inner core
Computer Modeling	Simulate core conditions to test hypotheses	Modeling iron crystal behavior
Volcanic Rock Analysis	Study materials brought to the surface by volcanic activity	Identifying core-mantle boundary composition

The Bigger Picture

Understanding Earth’s inner core is not just an academic exercise. It has practical implications for understanding the dynamics of our planet, including:

Magnetic Field Generation: The core’s composition and movement drive Earth’s magnetic field, which protects life from harmful solar radiation.
Geological Activity: Core processes influence volcanic activity, plate tectonics, and earthquake generation.
Planetary Comparisons: Studying Earth’s core can help us understand the interiors of other planets, such as Mars and Venus.

Fun Facts

The inner core’s temperature exceeds 5,000 degrees Celsius, hotter than the surface of the Sun.
It is roughly the size of the Moon but has a density similar to pure iron.
Seismic waves can travel through the inner core in just a few minutes, providing valuable data for scientists.

References

#EarthsCore, #SeismicWaves, #InnerCoreLayers, #Geophysics, #PlanetaryScience, #IronCrystals, #EarthStructure, #HiddenLayers, #Geology, #EarthquakeData, #CoolingEvents, #CoreResearch, #ScienceDiscovery, #EarthsHistory, #MagneticField

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Space Exploration

The Science Behind a Particle with Mass in One Direction

By Jonathan Bala January 2, 2025

The Science Behind a Particle with Mass in One Direction

The semi-Dirac fermion, a quasiparticle, has been discovered to exhibit mass in one direction and behave masslessly in another. This groundbreaking finding challenges classical physics and aligns with Einstein’s theory of relativity, offering new insights into quantum properties and particle behavior under extreme conditions.

Summary

A new type of quasiparticle, the semi-Dirac fermion, has been discovered by researchers at Penn State University.
Quasiparticles are energy packets in crystal structures that sometimes act as particles.
The semi-Dirac fermion demonstrates a unique property: it is massless in one direction but possesses mass in another direction.
This discovery builds on Einstein’s Special Relativity, which states that objects traveling at the speed of light cannot have mass.
Experiments to detect this quasiparticle used zirconium silicon sulfide (ZrSiS), cooled to near absolute zero and exposed to a powerful magnetic field.
The magnetic field created quantized energy states in the crystal, revealing the unusual behavior of the electrons.
The researchers generated a magnetic field 900,000 times stronger than Earth’s using a hybrid magnet at the National High Magnetic Field Laboratory in Florida.
Landau Levels, which are discrete states of electron energy, were observed but showed surprising discrepancies.
Infrared light and extreme cooling conditions were critical for studying the quantum properties of the material.
The discovery offers potential advancements in quantum computing and material science.
It underscores how collective electron behaviors in crystals can differ significantly from the behaviors of individual particles.
The phenomenon of quasiparticles challenges conventional understanding of particle behavior.
The findings have implications for new technologies, such as ultra-efficient semiconductors.
Further research may reveal additional quasiparticles and help refine quantum theories.
This discovery represents a significant milestone in particle physics and material science.

The Science Behind a Particle with Mass in One Direction — Experiments in particle physics explore mysteries. These mysteries exist at the smallest and largest scales. The smallest scale is called subatomic. Subatomic refers to particles smaller than atoms. The largest scale is called astronomical. Astronomical refers to things that relate to stars or space. The illustration by Olena Shmahalo is for U.S. Particle Physics.

Introduction to Particle Physics

Particle physics is the study of the smallest components of the universe and the forces that govern their interactions. It examines subatomic particles, such as quarks, leptons, and bosons, which form the foundation of matter. These particles interact through fundamental forces, including electromagnetism, gravity, and nuclear forces.

High-energy experiments, such as those conducted in particle accelerators, are essential for observing the behavior of these particles. Through these experiments, physicists uncover the mysteries of the subatomic world and gain insights into the origins and structure of the universe.

What Are Quasiparticles?

Quasiparticles are not elementary particles but rather collective behaviors of electrons or atoms in a material. They act like particles in some ways, possessing momentum, position, and energy. Quasiparticles emerge from the quantum properties of materials, providing a bridge between particle physics and material science.

The newly discovered semi-Dirac fermion is a quasiparticle with unusual properties. Unlike most particles, it appears massless when traveling in one direction and exhibits mass when traveling in another direction.

Experimental Discovery of the Semi-Dirac Fermion

To uncover the semi-Dirac fermion, researchers conducted experiments using zirconium silicon sulfide (ZrSiS) crystals. The experimental setup involved:

Cooling the crystal to near absolute zero.
Exposing it to a magnetic field 900,000 times stronger than Earth’s magnetic field.
Directing infrared light at the crystal to observe its quantum properties.

These extreme conditions caused electrons in the material to form Landau Levels, which are quantized energy states. However, the behavior of these levels deviated from expectations, leading to the discovery of the semi-Dirac fermion.

Implications of the Semi-Dirac Fermion

The discovery of this quasiparticle has far-reaching implications:

Quantum Computing: The unique properties of the semi-Dirac fermion may pave the way for advancements in quantum computing technologies.
Material Science: Understanding quasiparticles could lead to the development of ultra-efficient semiconductors and other materials.
Theoretical Physics: This finding challenges classical physics and supports Einstein’s theories of relativity.

Table 1: Key Properties of Semi-Dirac Fermions

Property	Description
Mass in One Direction	Possesses mass depending on direction of travel.
Massless in Another Direction	Behaves like light, traveling at its speed.
Observed in ZrSiS Crystals	Found in zirconium silicon sulfide material.
Linked to Landau Levels	Quantized energy states created by a magnetic field.

The Role of Magnetic Fields in the Discovery

The hybrid magnet at the National High Magnetic Field Laboratory was crucial for this discovery. By creating an extraordinarily strong magnetic field, researchers were able to observe how electrons inside the ZrSiS crystal responded.

When electrons are exposed to such a magnetic field, their motion becomes constrained, forming discrete energy states called Landau Levels. These levels depend on the mass of the electrons and the strength of the magnetic field. The semi-Dirac fermion disrupted this expected behavior, providing evidence of its unique properties.

Table 2: Experimental Conditions for Observing Semi-Dirac Fermions

Condition	Details
Temperature	Near absolute zero.
Magnetic Field Strength	900,000 times stronger than Earth’s.
Material	Zirconium silicon sulfide (ZrSiS).
Light Source	Infrared light to probe quantum properties.

Einstein’s Theory and the Semi-Dirac Fermion

Einstein’s Special Relativity states that particles traveling at the speed of light cannot have mass. The semi-Dirac fermion exemplifies this theory by behaving masslessly in one direction, where it travels at light speed. In the perpendicular direction, it encounters resistance, gaining mass.

Dr. Yinming Shao described the phenomenon using the analogy of a train switching tracks. On one track, the train moves freely (masslessly). On another, it experiences resistance (mass).

Potential Applications and Future Research

The semi-Dirac fermion’s unique behavior opens up possibilities for future technological advancements:

Semiconductors: Development of new materials with tunable electronic properties.
Quantum Devices: Enhanced precision and control in quantum computing.
Physics Models: Refinement of existing theories in particle physics and quantum mechanics.

Future research aims to explore other quasiparticles and understand their behavior under different conditions. The semi-Dirac fermion serves as a stepping stone for these investigations.

Facts About Quasiparticles

The term “quasiparticle” was coined by physicist Lev Landau in the 20th century.
Quasiparticles are not real particles but act like them in specific contexts.
They have been used to explain phenomena in superconductors and magnetic materials.
The discovery of quasiparticles often involves extreme experimental setups.

References

Penn State University Research on Semi-Dirac Fermions

#ParticlePhysics, #Quasiparticles, #SemiDiracFermion, #EinsteinRelativity, #QuantumMechanics, #HighEnergyPhysics, #MaterialScience, #QuantumComputing, #LandauLevels, #MagneticField, #PhysicsDiscovery, #ZrSiS, #AdvancedPhysics, #ScientificBreakthrough, #PhysicsExplained

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