neutron star | Ask Dr. Universe | Washington State University

^{Ask Dr. Universe} _{neutron star}

University Communications Network > Ask Dr. Universe > neutron star

What would happen if you put a baseball-sized piece of neutron star on the Earth? Would it fall to the core of the Earth and become part of the core or pass through the Earth? – MacKenzie, 12, Louisiana

June 18, 2025 melissamayer

Dear MacKenzie,

A neutron star is what’s left after a massive star runs out of fuel and explodes as a supernova.

I asked my friend Matthew Duez about it. He’s an astrophysicist at Washington State University.

He told me that a neutron star is the densest known object in the universe. Its mass is like the sun’s mass. But a neutron star is the size of a city.

When something is dense, it has lots of stuff—or mass—crammed into a small space.

Imagine if we took all the humans on the planet and squished them together. We mash and squash them until they fit … » More …

What is a supernova? – Grady, 7, Oklahoma

May 15, 2025 melissamayer

Dear Grady,

I was exploding with excitement to ask my friend Guy Worthey about supernovas. He’s an astronomer at Washington State University.

He told me a supernova is a very energetic explosion in space.

There are different kinds of supernovas. One kind—called a type II supernova—happens when a really big star dies.

“Why would a star bother to blow up?” Worthey said. “It seems dramatic. Human beings don’t blow up when they die.”

But humans don’t have cores that do nuclear fusion. Deep inside a star, protons and neutrons bang together and make new chemical elements. That nuclear fusion is why stars shine.

… » More …