Density Beyond Imagination

Neutron star matter is squeezed far beyond anything on Earth. Its density reaches about 10^17 kilograms per cubic meter, like packing the entire human population into a sugar cube.

The matter is layered:

• Crust: a crystalline lattice of iron nuclei, around 10 billion times stronger than steel
• Interior: a soup of free neutrons, with a few protons and electrons mixed in
• Core: possibly exotic states such as superfluid neutrons or even free quarks

What matter actually does at these pressures, its equation of state, is one of the biggest unsolved problems in nuclear physics. No laboratory on Earth can recreate it.