Why do neutron stars have magnetic fields?

 

If you're wondering why neutron stars have magnetic fields, you're not alone. These cosmic badasses are some of the most extreme objects in the universe, and their magnetic fields are no joke.

They can be millions or even trillions of times stronger than Earth's, and they can blast out beams of radiation that make them look like cosmic lighthouses.

Neutrons can have tiny magnetic moments, but they're not enough to explain the huge fields of neutron stars.

No, the real culprits are the protons and electrons that still lurk inside these dense balls of matter.

You see, when a massive star collapses into a neutron star, it squeezes its core so hard that most of the electrons and protons fuse into neutrons.

But not all of them.

Some of them survive in a thin crust on the surface, or in a superfluid state in the interior. And these charged particles can still move around, creating electric currents that generate magnetic fields.

The neutron star also spins very fast, because it conserves the angular momentum of its parent star. And as it spins, it drags the magnetic field lines along with it, twisting and amplifying them into a powerful dynamo.

This dynamo can also be fueled by convection, which is when hot fluid rises and cold fluid sinks, creating complex flows inside the star.

So there you have it. Neutron stars have magnetic fields because they have charged particles, rotation and convection. And these factors can combine to create some of the most mind-blowing magnets in the cosmos.

Why does the Earth have a magnetic field?

The Earth's magnetic field is generated by the movement of molten iron and other metals in the Earth's outer core.

This movement creates electric currents, which in turn produce the magnetic field. The process is known as a geodynamo.

The Earth's core is divided into two layers: a solid inner core and a liquid outer core. The outer core is about 2,250 kilometers (1,400 miles) thick and is composed of molten iron and nickel. The movement of this molten metal is caused by heat from the Earth's interior and the decay of radioactive elements.

As the molten metal moves, it creates electric currents through a process called electromagnetic induction.

These currents generate a magnetic field, which is strong enough to extend from the Earth's core to the surface and even into space.