Fifty years ago Sunday, astrophysicist Jocelyn Bell discovered a deep-space object that flashed every 1.3 seconds. This blinking object turned out to be a crushed star, smashed into a ball the size of a U.S. city when it ran out of gas and collapsed in on itself. These cosmic oddities, called pulsars, produce intense beams of light that us Earthlings detect as flashes or pulses.

Scientists have gained some understanding of these ultra-dense balls of matter. They now think pulsars could be used for navigation in deep space. The flashing stars could act as space beacons, like lighthouses, guiding spacecraft through the cosmos.

Here’s What We Know About Pulsars:

When a giant star like Betelgeuse (which is 600 times wider than the sun) runs out of fuel, it collapses in on itself and condenses into the densest known object in the universe, called a neutron star. A piece of a neutron star the size of a sugar cube would weigh about one billion tons here on Earth, according to NASA.

But many neutron stars can’t be detected, simply because they’ve spent most of their energy and don’t emit enough radiation. Pulsars, however, are neutron stars that still contain substantial amounts of radiation, and they shoot different types of radiation into the cosmos at consistent intervals. For instance, Bell picked up consistent ripples of pulsar radiowaves using a radio telescope. Pulsars can shoot a variety of radiation into space, such as X-rays and visible light. No two pulsars are alike, which makes them valuable beacons — just like each lighthouse has its own unique light signature.

Scientists think that pulsars have two powerful magnetic poles that funnel the stars’ radiation out of each pole. So as the star spins, we experience these two radiation beams as periodic flashes.

What’s an example of a pulsar?

One of the most well-known pulsars lives at the center of the Crab Nebula, a psychedelic cloud of comsic gas and dust that formed when a once great star exploded. Below is a view of the Crab Nebula captured in X-ray light.

How are scientists studying pulsars?

In early June, a SpaceX Falcon 9 rocket blasted into space with an instrument called NICER, short for Neutron Star Interior Composition Explorer. The instrument was then attached atop the International Space Station. NICER contains a whopping 56 spectrometer telescopes designed to scan radiation emissions from pulsars. Scientists plan to conduct basic science to better understand the size and density of pulsars, but also prove the feasibility of a futuristic X-ray GPS navigation system.

NICER

“Our primary goal is science,” NASA Scientist Keith Gendreau said in a statement about the mission. “But we can use the same pulsar measurements to demonstrate X-ray navigation. It’s rare that we scientists get to develop a multi-purpose experiment such as this one.

Future interstellar travelers may guide themselves through space by following these consistently flashing stars, just as mariners once depended on blinking lighthouses to follow — and avoid — Earth’s coastlines.

Photos via NASA (1, 2, 3, 4, 5)