[h=1]Earth's ancient magnetic field just got a lot older[/h] Early magnetism could have helped create conditions to support life.
30 July 2015 Earth developed a magnetic field at least four billion years ago, the latest research shows ? more than half a billion years earlier than thought.
The work, described in the 31 July issue of
Science[SUP]
1[/SUP], is a major step forward in understanding when and how Earth began to evolve into its modern form. An ancient magnetic field could have made the 500-million-year-old planet more hospitable to life, by preventing the Sun's powerful solar wind from stripping away the atmosphere.
The study helps put Earth in context with its planetary neighbours. ?The comparison between Earth and Mars is really striking,? says lead author John Tarduno, a geophysicist at the University of Rochester in New York. Mars also had a magnetic field at least 4 billion years ago, but the red planet
somehow lost its dense atmosphere and became a barren world. Yet Earth developed into
a hotbed of life....
