Space
How much would a sugar cube of neutron star weigh?
The short answer
About a trillion kilograms, according to NASA. A neutron star packs more mass than the Sun into a ball roughly 20 kilometres across, the size of a city. That makes its material so dense that a piece the size of a sugar cube would outweigh every car, truck and bus on Earth put together.
A neutron star is what is left when a giant star runs out of fuel and its core collapses. Gravity wins so completely that the atoms themselves give up: electrons are forced into protons, everything becomes neutrons, and a mass greater than the Sun's ends up crushed into a sphere you could drive across in twenty minutes.
Ordinary matter is almost entirely empty space. If an atom were a football stadium, the nucleus would be a pea on the centre spot. A neutron star is what you get when you throw away the stadium and keep only the peas, packed shoulder to shoulder. NASA's figure for the result is about a trillion kilograms per sugar cube.
The star's gravity is correspondingly absurd. Standing on its surface, if you could, you would weigh about a hundred billion times what you weigh now, and the surface would be so smooth that the tallest mountain would be a few millimetres high. Some neutron stars also spin hundreds of times a second. The universe does not do these things by halves.
Source
- Neutron StarsNASA Imagine the Universe