What is a light-day?
In November 2026 Voyager 1 will be so far from Earth that its signal, travelling at the speed of light, needs a full day to reach us. Launched in 1977, it is the most distant object people have ever built, and it is still talking.
One Light-Day is a sixteen-track series that follows both Voyagers from the launch pad, past the giant planets, to the edge of the Sun's influence and beyond. Every track has its own film, made from public NASA/JPL imagery, real mission data and our own animation. A new track arrives every few days until the day Voyager 1 crosses one light-day.
1979–1981
Closest approach. The Great Red Spot is seen in unprecedented detail. source
A plume on the limb of Io: the first active volcano found beyond Earth. source
The second flyby, and a new look at the Galilean moons. source
After Titan, Voyager 1 leaves the plane of the planets for good. source
Rings, spokes, and a gravity assist onward to Uranus. source
1990–2026
Voyager 1 crosses the boundary where the solar wind slows below the speed of sound. source
Voyager 1 crosses the heliopause and leaves the Sun’s bubble of plasma. source
The second twin crosses the heliopause too. source
Voyager 1 starts sending unreadable data. source
Engineers move code around a failed memory chip. Readable data returns after five months. source
Voyager 1 is so far away that its signal needs a full day to reach Earth. source
Sixteen tracks · one every few days