Earth’s Magnetic field tagged posts

Mapping the Milky Way’s Magnetic Field in 3D

We are all very familiar with the concept of the Earth’s magnetic field. It turns out that most objects in space have magnetic fields but it’s quite tricky to measure them. Astronomers have developed an ingenious way to measure the magnetic field of the Milky Way using polarized light from interstellar dust grains that align themselves to the magnetic field lines. A new survey has begun this mapping process and has mapped an area that covers the equivalent of 15 times the full moon.

Many people will remember experiments in school with iron filings and bar magnets to unveil their magnetic field. It’s not quite so easy to capture the magnetic field of the Milky Way though. The new method to measure the field relies upon the small dust grains which permeate space between the stars.

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Researchers track slowly splitting ‘Dent’ in Earth’s Magnetic Field

Earth’s magnetic field acts like a protective shield around the planet, repelling and trapping charged particles from the Sun. But over South America and the southern Atlantic Ocean, an unusually weak spot in the field – called the South Atlantic Anomaly, or SAA – allows these particles to dip closer to the surface than normal. Currently, the SAA creates no visible impacts on daily life on the surface. However, recent observations and forecasts show that the region is expanding westward and continuing to weaken in intensity. The South Atlantic Anomaly is also of interest to NASA’s Earth scientists who monitor the changes in magnetic strength there, both for how such changes affect Earth’s atmosphere and as an indicator of what’s happening to Earth’s magnetic fields, deep inside the globe...
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Magma Ocean may be Responsible for the Moon’s early Magnetic Field

The bottom-most layer of the moon's mantle melts to form a metal-rich "basal magma ocean" that sits on top of the moon's metal core. Convection in this layer may have driven a dynamo, creating a magnetic field which would have been recorded at the surface by the cooling lunar crust, including the samples brought back by Apollo astronauts. Credit: Aaron Scheinberg

The bottom-most layer of the moon’s mantle melts to form a metal-rich “basal magma ocean” that sits on top of the moon’s metal core. Convection in this layer may have driven a dynamo, creating a magnetic field which would have been recorded at the surface by the cooling lunar crust, including the samples brought back by Apollo astronauts. Credit: Aaron Scheinberg

Around 4 billion years ago, the Moon had a magnetic field that was about as strong as Earth’s magnetic field is today. How the Moon, with a much smaller core than Earth’s, could have had such a strong magnetic field has been an unsolved problem in the history of the Moon’s evolution...

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Earth’s magnetic field ‘simpler than we thought’

The geomagnetic field is critical to life on Earth. Without it, charged particles from the sun (the "solar wind") would blow away the atmosphere, scientists say. Credit: © SkyLine / Fotolia

The geomagnetic field is critical to life on Earth. Without it, charged particles from the sun (the “solar wind”) would blow away the atmosphere, scientists say. Credit: © SkyLine / Fotolia

Scientists have identified patterns in Earth’s magnetic field that evolve on the order of 1,000 years, providing new insight into how the field works and adding a measure of predictability to changes in the field not previously known. The discovery also will allow researchers to study the planet’s past with finer resolution by using this geomagnetic “fingerprint” to compare sediment cores taken from the Atlantic and Pacific oceans.

The geomagnetic field is critical to life on Earth. Without it, charged particles from the sun (the “solar wind”) would blow away the atmosphere, scientists say...

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