Many mechanisms have been postulated to explain how Earth’s magnetic field is generated. Although the Earth’s magnetic field resembles that of a bar magnet we must find another explanation for the field’s origin. Permanent magnets cannot exist at the temperatures found in the Earth’s core. We also know that the Earth has had a magnetic field for hundreds of millions of years. We cannot, however, simply attribute the existence of the present geomagnetic field to some event in the distant past. Magnetic fields decay, and we can show that the existing geomagnetic field would disappear in about 15,000 years unless there were a mechanism to continually regenerate it.
The actual process by which the magnetic field is produced in this environment is extremely complex, and many of the parameters required for a complete solution of the mathematical equations describing the problem are poorly known. However, the basic concepts are not difficult. For magnetic field generation to occur following conditions must be met:
- there must be a conducting fluid;
- there must be enough energy to cause the fluid to move with sufficient speed and with the appropriate flow pattern;
- there must be a “seed” magnetic field.
It is my conjecture that a mechanism which should continually regenerate Earth’s magnetic field could be Solar wind that powers various electric currents flowing in Earth’s ionosphere, and electrically charges the ground. Additionally, thunderstorms act as charge generators, charging negatively the earth surface, and charging the ionosphere positively. The above mentioned 3 conditions would be satisfied as follows:
- conducting fluid: ionosphere;
- energy and flow: Solar wind and Earth’s spin;
- “seed” magnetic field: the Barnett effect.
From classical electrodynamics we know that spinning electrically charged body will create a magnetic dipole with magnetic poles of equal magnitude but opposite polarity.
Earth is an electrically charged sphere that spins and orbits (rotates). If the above holds for an electron that indeed behaves like a tiny bar magnet, then perhaps it could also hold for Earth?
Considering also the Barnett effect, why could Earth not be able to generate its own magnetic field in this way, instead of purportedly originating from Earth’s hot (the Curie point) molten core?
ABOVE — Artist’s concept of the heliospheric current sheet. The spining Sun is located in the center. The current sheet circles the Sun’s equator like a wavy skirt around a ballerina’s waist.
BELOW — It would be interesting to find out if planets rotate around the Sun in the same direction as the Sun spins. It would seem that the heliospheric current sheet of spining Sun sweeps planets along, like a vortex:
The sun’s magnetic field permeates the entire solar system called the heliosphere. All nine planets orbit inside it. But the biggest thing in the heliosphere is not a planet, or even the sun. It’s the current sheet — a sprawling surface where the polarity of the sun’s magnetic field changes from plus (north) to minus (south). A small electrical current flows within the sheet, about 10−10 A/m². The thickness of the current sheet is about 10,000 km near the orbit of the Earth. Due to the tilt of the magnetic axis in relation to the axis of rotation of the sun, the heliospheric current sheet flaps like a flag in the wind. The flapping current sheet separates regions of oppositely pointing magnetic field, called sectors.
As Earth orbits the sun, it dips in and out of the undulating current sheet. On one side the sun’s magnetic field points north (toward the Sun), on the other side it points south (away from the Sun). South-pointing solar magnetic fields tend to cancel Earth’s own magnetic field. Solar wind energy can then penetrate the local space around our planet and fuel geomagnetic storms.
It is my conjecture that Earth’s spin and orbital rotation (and the rest of Solar system‘s planets and moons) is due to the Biefeld-Brown effect, which is powered by Solar wind, and aided by the spinning heliospheric current sheet. And the long-term stability of spins and orbital rotations rates is due to being continually regenerated by energy provided by Solar wind that is powering the Biefeld-Brown effect.
Mystery of the Lunar Ionosphere Solved
Every terrestrial planet with an atmosphere has an ionosphere. High above the planet’s rocky surface where the atmosphere meets the vacuum of space, ultraviolet rays from the sun break apart atoms of air. This creates a layer of ionized gas – an “ionosphere.”
Here on Earth, the ionosphere has a big impact on communications and navigation. For instance, it reflects radio waves, allowing shortwave radio operators to bounce transmissions over the horizon for long-range communications. The ionosphere also bends and scatters signals from GPS satellites, sometimes causing your GPS tracker to mis-read your position.
The first convincing evidence for an ionosphere around the Moon came in the 1970s from the Soviet probes Luna 19 and 22. Circling the Moon at close range, the orbiters sensed a layer of charged material extending a few tens of km above the lunar surface containing as many as 1000 electrons per cubic centimeter—a thousand times more than any theory could explain. Radio astronomers also found hints of the lunar ionosphere when distant radio sources passed behind the Moon’s limb.
The idea of an “airless Moon” having an ionosphere didn’t make much sense, but the evidence seemed compelling.
As a matter of fact, the Moon isn’t quite as airless as most people think. Small amounts of gas created by radioactive decay seep out of the lunar interior; meteoroids and the solar wind also blast atoms off the Moon’s surface. The resulting shroud of gas is so thin, however, that many researchers refuse to call it an atmosphere, preferring instead the term “exosphere.” The density of the lunar exosphere is about a hundred million billion times less than that of air on Earth—not enough to support an ionosphere as dense as the ones the Luna probes sensed.
For 40 years, the Moon’s ionosphere remained a mystery until Tim Stubbs of NLSI’s DREAM team at Goddard Space Flight Center published a possible solution earlier this year. The answer, he proposes, is moondust.
Stubbs–a 30-something scientist who wasn’t even born when the Moon’s ionosphere was discovered—read the accounts of Apollo 15 astronauts who reported seeing a strange glow over the Moon’s horizon. Many researchers believe the astronauts were seeing moondust. The Moon is an extremely dusty place, naturally surrounded by a swarm of dust grains–think PigPen in Charlie Brown. When these floating grains catch the light of the rising or setting sun, they create a glow along the horizon.
Stubbs and colleagues realized that floating dust could provide the answer. UV rays from the sun hit the grains and ionize them. According to their calculations, this process produces enough charge (positive grains surrounded by negative electrons) to create the observed ionosphere.
An ionosphere made of dust instead of gas is new to planetary science. No one knows how it will behave at different times of night and day or at different phases of the solar cycle, or how it might affect future radio communications and navigation on the Moon. NASA’s ARTEMIS probes (orbiting the Moon now) and the LADEE spacecraft (scheduled to launch in 2013 specifically for the purpose of studying the lunar exosphere) may yet reveal its habits. Updates may be expected in less than 40 years.