A powerful radio pulse briefly outshone all other objects in the sky from a decades-old NASA satellite. The Relay 2, launched in 1964 as an experimental communications device, had been dead for over 50 years. Astronomers speculate that the flash may have resulted from a freak micrometeorite impact or a random electrical spark. The satellite’s onboard electronics stopped working in 1967, leaving it to orbit Earth with only its metal hull intact.
Source: https://www.newscientist.com/article/2485157-dead-nasa-satellite-unexpectedly-emits-powerful-radio-pulse