No, not trousers from the sixties (or was it the seventies?).
The Iridium satellite constellation is a system of 66 active communication satellites and spares around the Earth. It allows worldwide voice and data communications using handheld devices. The Iridium network is unique in that it covers the whole earth, including poles, oceans and airways.
The satellites used are frequently visible in the night sky as short-lived bright flashes, known as Iridium flares.
You can be notified of when the satellites will pass across your location. Take your group outside and impress them with your knowledge of the night sky by ‘predicting’ a flash. You might want to practice first but apparently you can even get a notification to your mobile of impending passes by the satellites.