Spacecraft could one day navigate through the cosmos using a particular type of dead star as a kind of GPS.
German scientists are developing a technique that allows for very precise positioning anywhere in space by picking up X-ray signals from pulsars.
These dense, burnt-out stars rotate rapidly, sweeping their emission across the cosmos at rates that are so stable they rival atomic clock performance.
This timing property is perfect for interstellar navigation, says the team.
If a spacecraft carried the means to detect the pulses, it could compare their arrival times with those predicted at a reference location. This would enable the craft to determine its position to an accuracy of just five kilometres anywhere in the galaxy.
"The principle is so simple that it will definitely have applications," said Prof Werner Becker from the Max-Planck Institute for Extraterrestrial Physics in Garching.
"These pulsars are everywhere in the Universe and their flashing is so predictable that it makes such an approach really straightforward,"