Here's why:

* Massive Stars: Neutron stars form from the core collapse of massive stars (at least 8 times the mass of our Sun).

* Supernova: This collapse triggers a supernova explosion, blasting the outer layers of the star into space.

* Extreme Density: The core, under immense pressure, collapses further, squeezing protons and electrons together to form neutrons. This creates a incredibly dense object packed with neutrons.

* Size: Neutron stars are incredibly small, typically only about 12 miles (20 kilometers) in diameter, but they can be 1.5-3 times the mass of our Sun.

Let me know if you have any other questions!