Voyager 1 is still talking to us
From 24 billion kilometres away.
Voyager 1 crossed into interstellar space in 2012 and, half a century after launch, still transmits science data back to Earth. Its 22.4-watt radio signal takes over 22 hours to reach us. NASA's Deep Space Network listens carefully, and the spacecraft — running on a plutonium battery — should keep whispering until at least 2030.
Editor's Note
The longest conversation in human history is the one we are still having with a machine we launched before most of us were born.
