Unlocking Earth's ancient magnetic past

See allHide authors and affiliations

Science  31 Jul 2015:
Vol. 349, Issue 6247, pp. 490-492
DOI: 10.1126/science.349.6247.490-l

The magnetic field protects Earth's surface from deadly cosmic radiation and provides clues about the planet's interior. Tarduno et al. found that some of the oldest minerals on Earth, Jack Hills zircons, preserved a record of a magnetic field over 4 billion years ago (see the Perspective by Aubert). Earth's magnetic field appears to have been fully operational a mere few hundred million years after the planet formed. This suggests an early start for plate tectonics and an ancient cosmic radiation shield that was important for habitability.

Science, this issue p. 521; see also p. 475

Stay Connected to Science

Navigate This Article