The Earth’s magnetic field will be lost.

 

The Earth’s magnetic field will be lost.

The Earth’s core contains iron. This creates a strong magnetic field that protects you against damaging rays from the sun and outside the solar system (cosmic rays).

These harmful rays reach the Earth’s atmosphere but don’t get to you on the surface.

You may spot them in the sky as beautiful southern and northern lights.

If our planet stops spinning, the protection of the magnetic field is lost, and these harmful rays may get to the Earth’s surface and affect people’s health.

Furthermore, the Earth’s magnetic field helps direct migrating birds, and without this, birds can get lost as they travel to new destinations.

This magnetic-field engine, known as a dynamo, has been chugging along for billions of years. Scientists think that the current core arrangement may have settled into place about 1.5 billion years ago, according to 2015 research that found a leap in the magnetic field's strength around then. But Tarduno and his team have found evidence for a magnetic field on Earth in the planet's oldest minerals, zircons, dating back 4.2 billion years, suggesting that activity in the core has been creating magnetism for a very long time. 

It isn't clear why the dynamo got started, Tarduno told Live Science, though it's possible that the enormous planetary impact that created the moon might have been the key driver. This impact, which occurred perhaps 100 million years after Earth came together, could have shaken up any stratification, or layering, of materials in Earth's core: Imagine shaking up a bottle of oil and water on a planetary scale. This disruption could have promoted the convection that still drives Earth's dynamo today.