Neutron stars are strange cosmic beasts. Stellar corpses that are several times the mass of our Sun but only about the width of Manhattan, they can contain a mountain’s worth of star-stuff within the space of a sugar cube, creating all sorts of weird physics that requires funny-sounding names like “quark-gluon plasma” to even try to describe what’s going on. The video above, created by Munich-based design studio Kurzgesagt (which means “in a nutshell” in German) illustrates how neutron stars form and what we think is happening on, around, and inside them.

See more In a Nutshell videos by Kurzgesagt on YouTube here, and find some interesting neutron star facts below:

• Atomic nuclei are 99.9999999999999% empty space, but inside a neutron star all that space is taken up by neutrons and mashed-together protons and electrons.

• The gravity on the surface of a neutron star would be two hundred billion times more than on Earth, and the escape velocity needed to leave it would be half the speed of light!

• Neutron stars, although extremely hot, are nearly invisible in optical wavelengths. Most of their radiation is emitted in x-ray and radio.

• The magnetic field of a neutron star is more than a trillion times that of Earth’s – so strong that atoms within it get squeezed into cigar shapes!

• If you dropped 1kg of matter onto a neutron star (not advised) the energy released would be equal to a five megaton hydrogen bomb!

• Neutron stars can only be 1.4–3 times the mass of the Sun. Any more than that and they’d become black holes.

Sources:
Black Holes and Neutron Stars by Cole Miller
Dave Goldberg, Ask a Physicist on io9.com
Chandra X-ray Observatory
KIPAC (Kavli Institute)