Where is earth magnetosphere

This is called the Dynamo Theory and it explains how the Earth's magnetic field is sustained. Another feature that distinguishes the Earth magnetically from a bar magnet is its magnetosphere. At large distances from the planet, this dominates the surface magnetic field. Electric currents induced in the ionosphere also generate magnetic fields. Such a field is always generated near where the atmosphere is closest to the Sun, causing daily alterations that can deflect surface magnetic fields by as much as one degree.

Typical daily variations of field strength are about 25 nanoteslas nT i. The currents in the core of the Earth that create its magnetic field started up at least 3, million years ago.

Magnetometers detect minute deviations in the Earth's magnetic field caused by iron artifacts , kilns, some types of stone structures, and even ditches and middens in archaeological geophysics. Using magnetic instruments adapted from airborne magnetic anomaly detectors developed during World War II to detect submarines, the magnetic variations across the ocean floor have been mapped.

The basalt — the iron-rich, volcanic rock making up the ocean floor — contains a strongly magnetic mineral magnetite and can locally distort compass readings. The distortion was recognized by Icelandic mariners as early as the late 18th century. More important, because the presence of magnetite gives the basalt measurable magnetic properties, these magnetic variations have provided another means to study the deep ocean floor.

When newly formed rock cools, such magnetic materials record the Earth's magnetic field. Frequently, the Earth's magnetosphere is hit by solar flares causing geomagnetic storms , provoking displays of aurorae. The short-term instability of the magnetic field is measured with the K-index.

Recently, leaks have been detected in the magnetic field, which interact with the Sun's solar wind in a manner opposite to the original hypothesis.

During solar storms , this could result in large-scale blackouts and disruptions in artificial satellites. Based upon the study of lava flows of basalt throughout the world, it has been proposed that the Earth's magnetic field reverses at intervals, ranging from tens of thousands to many millions of years , with an average interval of approximately , years.

There is no clear theory as to how the geomagnetic reversals might have occurred. Some scientists have produced models for the core of the Earth wherein the magnetic field is only quasi-stable and the poles can spontaneously migrate from one orientation to the other over the course of a few hundred to a few thousand years. Other scientists propose that the geodynamo first turns itself off, either spontaneously or through some external action like a comet impact , and then restarts itself with the magnetic "North" pole pointing either North or South.

External events are not likely to be routine causes of magnetic field reversals due to the lack of a correlation between the age of impact craters and the timing of reversals.

Regardless of the cause, when the magnetic pole flips from one hemisphere to the other this is known as a reversal, whereas temporary dipole tilt variations that take the dipole axis across the equator and then back to the original polarity are known as excursions.

Studies of lava flows on Steens Mountain , Oregon, indicate that the magnetic field could have shifted at a rate of up to 6 degrees per day at some time in Earth's history, which significantly challenges the popular understanding of how the Earth's magnetic field works. Paleomagnetic studies such as these typically consist of measurements of the remnant magnetization of igneous rock from volcanic events.

Sediments laid on the ocean floor orient themselves with the local magnetic field, a signal that can be recorded as they solidify. Navigation: Low-frequency navigation signals degraded for brief intervals. Earth's magnetosphere. Earth Sun Relationship:.

Space Weather Impacts On Climate. This magnetic field is known as the geodynamo. Pinning down exactly when the magnetic field formed could help scientists figure out what generated it to begin with. As rocks form and cool, the electrons within individual grains can shift in the direction of the surrounding magnetic field.

Once the rock cools past a certain temperature, known as the Curie temperature, the orientations of the electrons are set in stone, so to speak. In , a separate research group that had also started studying the Jack Hills zircons argued that they found evidence of magnetic material in zircons that they dated to be 4.

But Borlina notes that the team did not confirm whether the magnetic material they detected actually formed during or after the zircon crystal formed 4. Borlina, Weiss, and their colleagues had collected rocks from the same Jack Hills outcrop, and from those samples, extracted 3, zircon grains, each around micrometers long — about the width of a human hair. Using standard dating techniques, they determined the age of each zircon grain, which ranged from 1 billion to 4.

Around crystals were older than 3. The team isolated and imaged those samples, looking for signs of cracks or secondary materials, such as minerals that may have been deposited on or within the crystal after it had fully formed, and searched for evidence that they were significantly heated over the last few billion years since they formed.

Of these , they identified just three zircons that were relatively free of such impurities and therefore could contain suitable magnetic records.

The team then carried out detailed experiments on these three zircons to determine what kinds of magnetic materials they might contain. They eventually determined that a magnetic mineral called magnetite was present in two of the three zircons.

The side of the magnetosphere facing away from the sun - the nightside - stretches out into an immense magnetotail, which fluctuates in length and can measure hundreds of Earth radii, far past the moon's orbit at 60 Earth radii. NASA heliophysics studies the magnetosphere to better understand its role in our space environment.

Such research helps unravel the fundamental physics of space, which is dominated by complex electromagnetic interactions unlike what we experience day-to-day on Earth. By studying this space environment close to home, we can better understand the nature of space throughout the universe. Additionally, space weather within the magnetosphere - where many of our spacecraft reside - can sometimes have adverse effects on space technology as well as communications systems.

Better understanding of the science of the magnetosphere helps improve our space weather models. NASA's studies of the magnetosphere include research into: understanding the nature of the electromagnetic phenomena in near-Earth space; how near-Earth space responds to external and internal stimuli; how the coupled middle and upper atmosphere respond to external factors; and how the various regions of the magnetosphere and upper atmosphere interact with each other. Additionally, instruments on other NASA missions -- for example, Juno, which observes Jupiter -- observe the magnetosphere of other planets.

Earth is surrounded by a giant magnetic bubble called the magnetosphere, which is is part of a dynamic, interconnected system that responds to solar, planetary, and interstellar conditions. Magnetospheres A magnetosphere is the region around a planet dominated by the planet's magnetic field.