NASA is inviting people to flash a light towards the sky after sunset on Tuesday 17 November to celebrate Voyager 1 approaching a distance no other human-made object has reached. The spacecraft is about to become the first to travel one light-day from Earth, nearly half a century after launch.

Aerial view of the Canberra Deep Space Communication Complex, photographed in April 2010. Photo: Robert Kerton / CSIRO / Wikimedia Commons, CC BY 3.0, cropped resized and compressed, modified.