Ancient Roots of Earth Magnetism


The Earth may have developed a magnetic field four billion years ago, more than half a billion years earlier than previously thought.

John Tarduno of the University of Rochester in New York and his colleagues measured weak magnetic signals from iron-bearing minerals trapped inside four-billion-year-old zircon crystals in the Jack Hills region of Western Australia . They found that the intensity of the magnetic field fluctuated, from a value similar to the current field (about 25 microteslas) to about 12% of it.

An ancient magnetic field when the planet was only about 500 million years old would have been a good, if imperfect, shield against the solar wind. This could have made the young planet more hospitable to life, the authors say.

Science 349521–524 (2015)

About this article

Verify currency and authenticity via CrossMark

Quote this article

Ancient roots of terrestrial magnetism.
Nature 524, 9 (2015).

Download quote

  • Posted:

  • Date of issue:

  • DO I:


About Author

Comments are closed.