The streaks of light in NASA's latest image look like air traffic routes, but it's a different way of looking at the entire sky. The arcs are actually tracing X-rays, recorded by the Neutron star Interior Composition Explorer, known as NICER.

NICER acts as a detector of cosmic sources from the International Space Station, which orbits the Earth every 93 minutes. NICER keeps tracking those sources, even at night.

This map of our sky represents the first 22 months of NICER's work, taking data from its nighttime observations. The arcs follow X-rays and energetic particle strikes. The most travelled pathways tracked by NICER reveal the brightest and most prominent arcs.

One of NICER's goals is to determine the size of neutron stars, which are the remains of dense stars. Determining the size of those remains with precision could unravel the mystery of what form matter takes in their dense cores. Pulsars, or rapidly spinning neutron stars that look like they're pulsing with light, serve as targets for NICER.

NICER can also study pulsar X-rays to determine the detector's speed and position for itself, acting like a galactic GPS system, the agency said. This experiment could pave the way for spacecraft to use the technology in the future and even navigate themselves across our solar system, or even beyond it.

In 2017, the first-ever detection of two neutron stars colliding was made.

The collision created the first observed instance of a single source emitting ripples in space-time, known as gravitational waves, as well as light, which was released in the form of a 2-second gamma ray burst. The collision also created heavy elements such as gold, platinum and lead, scattering them across the universe in a kilonova -- similar to a supernova -- after the initial fireball.

Neutron stars are the smallest in the universe, with a diameter comparable to the size of a city like Chicago or Atlanta. They are the leftover remnants of supernovae. But they are incredibly dense, with masses bigger than that of our sun. So think of the sun, compressed into a major city.