Guarding life on Earth
Without Earth's molten outer core, life as we know it would not exist. The movement of liquid iron in the outer core, caused by convection and Earth's rotation, generates a magnetic field around our planet. This magnetosphere deflects the charged particles streaming toward us from the Sun. Without this invisible shield, the barrage of ions from the solar wind would make Earth's surface uninhabitable.
The iron core of Mars, in contrast, has cooled and almost entirely solidified-so Mars has only a tiny magnetic field. With little protection, Mars is bombarded by deadly ions, making life on its surface virtually impossible.
Topic: Earth Science
Subtopic: Earth Structure
Keywords: Astrophysics, Magmas, Life (Biology), Earth (Planet)--Core, Magnetic fields, Astrogeology, Mars, Solar wind