A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star, such stars are composed almost entirely of neutrons.It is so dense that one teaspoon (5 milliliters) of its material would have a mass over 5.5×1012 kg, about 900 times the mass of the Great Pyramid of Giza (Can you imagine 900 pyramids on a tiny spoon?). Most are no larger than the size of Manhattan, and spin at more than 40,000 revolutions per minute. The gravity of a neutron star is nearly beyond comprehension. If you let something drop from a height onto the star’s surface, that material will be moving at a third of the speed of light; upon impact! The energy release is monumental; a marshmallow traveling at that speed would explode like a nuclear weapon. 

neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star, such stars are composed almost entirely of neutrons.
It is so dense that one teaspoon (5 milliliters) of its material would have a mass over 5.5×1012 kg, about 900 times the mass of the Great Pyramid of Giza (Can you imagine 900 pyramids on a tiny spoon?). Most are no larger than the size of Manhattan, and spin at more than 40,000 revolutions per minute. 
The gravity of a neutron star is nearly beyond comprehension. If you let something drop from a height onto the star’s surface, that material will be moving at a third of the speed of light; upon impact! The energy release is monumental; a marshmallow traveling at that speed would explode like a nuclear weapon.