What do you get when a star the size of a small city collapses?

The answer is a colossal 40-trillion-mile-long beam of matter and antimatter.

NASA spotted the “tiny” spinning pulsar an incredible 1,600 light years away from Earth.

The super-dense star – dubbed J2030 – rotates a dizzying three times per second and blasts through space at about a million miles per hour.

Astronomers actually spotted the massive beam in 2020.

But it is so long that their high-tech kit wasn’t able to see the ends.

Only when experts decided to give it another shot using the Chandra X-ray Observatory were they stunned to find it was three times bigger than predicted.

“It’s amazing that a pulsar that’s only ten miles across can create a structure so big that we can see it from thousands of light-years away,” said Martjin de Vries from Stanford University.

“With the same relative size, if the filament stretched from New York to Los Angeles the pulsar would be about 100 times smaller than the tiniest object visible to the naked eye.”

Experts think the beam may help them finally understand a question that has bugged them for centuries.

Why is the Milky Way filled with so many positrons, a type of antimatter counterpart to electrons?

“This likely triggered a particle leak,” said Roger Romani, also from Stanford University.

“The pulsar wind’s magnetic field linked up with the interstellar magnetic field, and the high-energy electrons and positrons squirted out through a nozzle formed by connection.”

Their research is published in the Astrophysical Journal.

This article originally appeared on The Sun and was reproduced here with permission.