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Why Are Neutron Stars So Heavy?


What’s so small that it’s super heavy and just a teaspoon of it would weigh 10 million tons? If you guessed a neutron star, you’re right. We can barely comprehend this kind of scale, but it certainly exists. What’s with this insanity? What makes neutron stars so heavy?


1. Neutron stars form from collapsed stars.
The reason neutron stars are so heavy starts with how they form. When a star that’s 10 to 29 solar masses (that’s between 10 and 29 times more massive than our sun) dies in a supernova explosion then collapses inward due to gravity, it becomes a neutron star.


2. All that mass is crammed into a tiny space.
The material that isn’t ejected during the supernova explosion gets packed into a very condensed space, usually a city-sized ball. Within this city-sized ball is material equaling about 1.3 to 2.5 solar masses. That’s more mass than the Sun packed into a space you can fit on Earth. This makes neutron stars incredibly heavy.

3. Why are they called neutron stars?
One last fact about neutron stars. They’re called neutron stars because as they’re forming, the compression and heat are so intense that protons and electrons melt, essentially, and form neutrons.