Navigation satellites are located at an altitude of 20,000 kilometers and can be navigated by receiving signals within their coverage. In the deep space of more than 20000 kilometers, a new navigation system is needed. Astronomers have proposed several possible navigation systems, and the most talked about is pulsar navigation. Pulsars are a kind of neutron stars, whose magnetic pole direction can produce radio or X-ray radiation, When the rotation axis does not coincide with the magnetic pole, and the rotation axis sweeps across the earth, pulses will be generated. Some pulsars have very good rotation stability, which can be compared with the best atomic clock on earth
these pulsars are also called atomic clocks in the universe. If their signals can be received and their positions can be known, these pulsars can be used for interstellar navigation.
Factors affecting the rotational stability of Pulsars