A city-sized star that outweighs the Sun.
A city-sized star that outweighs the Sun. That's a neutron star — and it gets stranger from there. When a massive star exhausts its fuel, it collapses in a supernova. The core gets crushed so violently that protons and electrons are squeezed into neutrons, leaving behind a sphere roughly twenty kilometres across. Scoop out a teaspoon of that material and it would weigh about a billion tonnes here on Earth. Not a mountain — a billion tonnes in a teaspoon. Surface gravity runs billions of times stronger than what holds you to the ground right now. Some neutron stars rotate hundreds of times every second, sweeping beams of radiation across space like a lighthouse. We call those pulsars, and they keep time so precisely they rival atomic clocks. Follow Deep Field Vault for more of the universe's genuinely extreme physics.