To solve a mystery about Earth's core, scientists looked to the moon. Viewed from space, Earth is a serene blue sphere. But beneath its surface, there is a roiling mass of liquid, nickel-iron alloy and solid iron almost 6,000 miles in diameter. The inner and outer core comprise almost a third of Earth's mass, and together they generate a magnetic field that shields life on this planet from harmful charged particles emanating from the sun. But Earth's core, perhaps, can't take all of the credit for saving humanity.
In a study published Wednesday in the journal Earth and Planetary Science Letters, scientists from the National Center for Scientific Research in France say the the moon plays a key role keeping life on Earth safe. Although the moon sits some 230,000 miles away, researchers believe its gravitational tug churns iron alloy in the core, which, in turn, helps maintain the magnetic field that protects our planet.
