Earth’s magnetic field much older than previously thought

New York, July 31 (IANS) The Earth’s magnetic field is at least four billion years old, up from the previous estimates of 3.45 billion years, researchers from University of Rochester have found.

Earth’s magnetic field protects the atmosphere from solar winds – streams of charged particles shooting from the Sun.

The magnetic field helps prevent the solar winds from stripping away the atmosphere and water, which make life on the planet possible.

Given the importance of the magnetic field, scientists have been trying to determine when it first arose, which could, in turn, provide clues as to when plate tectonics got started and how the planet was able to remain habitable.

“A strong magnetic field provides a shield for the atmosphere,” said John Tarduno, geophysicist at University of Rochester and a leading expert on Earth’s magnetic field.

“This is important for the preservation of habitable conditions on Earth,” he added.

Earth’s magnetic field is generated in its liquid iron core and this “geodynamo” requires a regular release of heat from the planet to operate.

Today, that heat release is aided by plate tectonics, which efficiently transfers heat from the deep interior of the planet to the surface.

But, according to Tarduno, the time of origin of plate tectonics is hotly debated, with some scientists arguing that Earth lacked a magnetic field during its youth.

The new results, published in the journal Science, are based on the record of magnetic field strength fixed within magnetite found within zircon crystals collected from the Jack Hills of Western Australia.

The zircons were formed over more than a billion years and have come to rest in an ancient sedimentary deposit.

By sampling zircons of different age, the history of the magnetic field can be determined.

Scientists believe that Mars had an active geodynamo when that planet was formed, but that it died off after four billion years.

As a result, Tarduno says, the Red Planet had no magnetic field to protect the atmosphere, which may explain why its atmosphere is so thin.

“It may also be a major reason why Mars was unable to sustain life,” he concluded.

Leave a Reply

Please enter your comment!

The opinions, views, and thoughts expressed by the readers and those providing comments are theirs alone and do not reflect the opinions of or any employee thereof. is not responsible for the accuracy of any of the information supplied by the readers. Responsibility for the content of comments belongs to the commenter alone.  

We request the readers to refrain from posting defamatory, inflammatory comments and not indulge in personal attacks. However, it is obligatory on the part of to provide the IP address and other details of senders of such comments to the concerned authorities upon their request.

Hence we request all our readers to help us to delete comments that do not follow these guidelines by informing us at Lets work together to keep the comments clean and worthful, thereby make a difference in the community.

Please enter your name here