Unbelievable MATTER's LIMIT The most massive known neutron star, which lies over 3,600 light-years away in the northern constellation Camelopardalis || Watch how NASA’s Neutron star Interior Composition Explorer (NICER) is helping physicists peer into the hearts of neutron stars, the remains of massive stars that exploded in supernovae. Scientists want to explore the nature of matter inside these objects, where it exists on the verge of collapsing into black holes. To do so, scientists need prec