17.5 Earth's Magnetic Field
Earth's magnetic field acts like an invisible shield that surrounds the planet and stretches into space. It is similar to the field of a bar magnet, with a north and south pole, but unlike a regular magnet, it constantly shifts and can even flip over time.
This magnetic field is essential because it protects the Earth from dangerous solar winds and cosmic radiations by pushing away harmful charged particles. It also helps with navigation, guiding both humans and animals like migratory birds and sea turtles.