Leaving the solar system
Five spacecraft are coasting out of the solar system, never to return — and every second, they get farther away. Two of them, the Voyagers, have already crossed into interstellar space. Watch the distances climb in real time, and see how long a signal now takes to reach each one across the dark.
The most distant human-made object ever. In 2012 it slipped past the heliopause into interstellar space, and around November 2026 it becomes the first craft a full light-day from Earth — a signal now takes almost a day to reach it.
The only spacecraft to visit all four giant planets, and the second to reach interstellar space, in 2018. Its plutonium heart is fading — instruments are being switched off one by one to keep it whispering home a few more years.
The first craft to cross the asteroid belt and fly past Jupiter. Its last faint signal came in January 2003; it now drifts on in silence, aimed at a star it will reach in about two million years.
The first spacecraft to fly past Saturn, using Jupiter's gravity to get there. Contact was lost in 1995 as its power dwindled — a silent ambassador still coasting outward, carrying its map back to Earth.
Flew past Pluto in 2015 and the tiny world Arrokoth in 2019 — the most distant object ever explored up close. Still healthy, still hunting the Kuiper Belt, and one day it too will cross into interstellar space.
Distances are computed from published NASA/JPL trajectory data and tick at each craft's real recession speed. Figures for the silent Pioneers are estimates — there is no signal left to confirm them. They still talk to the Deep Space Network (the ones that can).
The Sun blows a vast bubble of charged particles called the heliosphere. Its outer shore — the heliopause, where the solar wind finally gives way to the gas between the stars — sits about 120 times farther from the Sun than Earth. Voyager 1 crossed it in 2012 and Voyager 2 in 2018, becoming the first two objects ever to travel in true interstellar space. New Horizons and the Pioneers are still inside the bubble, heading for the same frontier.
Each craft carries a note to whoever — or whatever — might one day find it. The Voyagers bear the Golden Record: greetings in 55 languages, the sound of a kiss and a mother's first words to her child, whale song, and music from Bach to Chuck Berry, etched into gold-plated copper to last a billion years.
The Pioneers carry an engraved plaque — a man, a woman, and a map showing where in the galaxy their makers live. They are the first letters humanity ever addressed to the stars, and they will outlast everything else we have ever built.
The Voyagers run on the slow heat of decaying plutonium, and it is nearly spent. Each year they lose a few more watts, and engineers switch off another instrument to keep the radio alive. Some time in the 2030s the last one will fall silent — and the Voyagers will become what the Pioneers already are: silent ambassadors, coasting on forever, carrying their records into a night that never ends.
They will not come close to another star for tens of thousands of years. But they are still out there, right now, getting farther with every second on the counter above.
Most distant
Voyager 1
~26 billion km — a light-day out in late 2026
On the road since
1972
Pioneer 10, the trailblazer
Fastest
~17 km/s
Voyager 1 — 61,000 km/h, forever
In interstellar space
2 craft
Both Voyagers, past the heliopause