ELI5: Explain Like I'm 5

Neutron stars

Okay kiddo, so you know what stars are right? Big balls of fire in the sky that shine brightly all night long. Well, some stars, when they are at the end of their lives, get really really heavy and explode in a big explosion called a supernova. This explosion can be so big that it can leave behind a tiny little ball called a neutron star.

Imagine you have a big marshmallow in your hand. Now squish it really hard so it becomes super tiny, smaller than a pea. That's kind of what happens to a star when it becomes a neutron star. They can be as tiny as a city, but they are still super heavy, like a mountain.

One of the coolest things about neutron stars is that they spin around and around so fast that they are like a super-fast spinning top. They can spin more than 700 times in just one second! This is because when the star explodes, it will sometimes start spinning around really fast, just like you would spin yourself around in circles.

Neutron stars are also super strange because they are so heavy that they can make gravity really, really strong. So strong, in fact, that if you got too close to one, you would get squished into a pancake! That's why you have to be really careful around neutron stars.

Scientists still have a lot to learn about neutron stars, but they study them to learn more about the universe and how it works. So, just remember that neutron stars are tiny, super-heavy, spin fast, and have really strong gravity.