Taxonomy term

magnetic field

Red Planet Roundup: February 2018

With two rovers patrolling the surface of Mars, six spacecraft orbiting above it, and scientists here on Earth studying the Red Planet from afar, new findings are announced often. Here are a few of the latest updates.

09 Feb 2018

Earth's magnetic field illuminates ocean temperatures

As Earth warms, the atmosphere isn’t the only place where temperatures are rising — the oceans are absorbing most of the excess heat, but precisely how much is unclear. Using recently launched satellites that can measure subtle fluctuations in Earth’s magnetic field, researchers are devising a method that may help refine ocean temperature measurements and clarify how much heat the oceans are storing.

16 Mar 2017

Scientists map U.S. geoelectric hazards

During solar storms, electrons and protons collide with Earth’s atmosphere, disrupting the geomagnetic field and sometimes creating the flashing waves of colorful light in the night sky we know as auroras. But these same storms — if strong enough — have the potential to severely damage power grids.

19 Jan 2017

Weak magnetic field may have triggered Earth's first mass extinction

For about the first 3 billion years of life, the only living organisms on Earth were microscopic. The Ediacaran Period, between 635 million and 541 million years ago, saw the rise of the first large-scale life, most of which then went extinct at the period’s close — a collapse that scientists have yet to explain. Now, researchers may have found one of the extinction’s drivers: rapid flip-flopping of Earth’s magnetic field — wherein the field’s north and south poles reverse — that could have left the planet and Ediacaran organisms vulnerable to bombardment by harmful cosmic radiation.

08 Jul 2016

Magnesium part of Earth's magnetic field engine

Earth’s magnetic field, which arises from convective flows in the planet’s core, known as the geodynamo, has existed for at least 3.4 billion years, meaning that the field-generating processes must have existed for that long as well. But what exactly those processes have looked like throughout Earth’s history, particularly early on, has been poorly understood. In a new study, researchers suggest that magnesium mineral formation in the core is a previously unrecognized but important piece of the puzzle.

26 Apr 2016

Magnetic field around since Hadean

Earth’s magnetic field might have been shielding the planet from solar radiation and contributing to its habitability 770 million years earlier than previously recognized, according to a new study in Science.
17 Dec 2015

Benchmarks: May 6, 1852: Edward Sabine links the geomagnetic and sunspot cycles

At the beginning of the 19th century, little was understood about Earth’s magnetic field, but interest in its workings had begun to grow, especially in Europe. That the magnetic field exists had long been recognized, and magnetic compasses had aided in navigation for centuries, particularly at sea where fixed landmarks are hard to come by. Not surprisingly, the increased attention emerging around the turn of the century came from naval and shipping interests, which recognized that an accurate understanding of the field’s behavior would be a boon to their fleets.

By this time, the underlying physical explanation for the magnetic field had also become a major source of scientific curiosity. In the preceding two centuries, observers had measured differences in the field’s intensity, inclination and declination — the angle between magnetic and true north — between locations, as well as changes in those properties at the same location, both over varying lengths of time. Others had noted the synchronized occurrence of colorful atmospheric auroras with widespread disturbances in the magnetic field, termed magnetic storms.

It was clear the planet’s magnetic field was an inconstant and complex phenomenon, and many eminent scientists saw it as the next great natural mystery to unravel.

13 May 2014

Ancient meteorites reveal early magnetic fields

Even before the birth of the planets, our solar system was hardly a lonely place. Small rocky bodies, called planetesimals, filled the inner solar system, eventually colliding together to form the planets. Now a new look at a group of ancient meteorites shows that at least some planetesimals generated their own magnetic fields — a feat many scientists thought extremely difficult for such small astronomical bodies. The work also has scientists rethinking how planets formed.

21 Jan 2009

Of molten iron and magnetism

Since 1999, the German satellite CHAMP (CHAllenging Mini-satellite Payload) has swirled around Earth, keeping watch as the planet’s magnetic field waxes and wanes over time. CHAMP’s continuous measurements of Earth’s field have created a finely detailed picture of how the field changes both in space and in time — and by extension, how the movement of the molten iron in Earth’s outer core ebbs and flows. And thanks to these data, researchers report, they can now track even small-scale, rapid fluctuations in the field’s strength around the planet.

28 Aug 2008