Voyager 1

The farthest human-made object, still whispering home from interstellar space

Key facts

Launched: 5 September 1977, Cape Canaveral, on a Titan IIIE-Centaur rocket
Where it is now: About 171 AU from the Sun, in interstellar space (as of 8 September 2026)
Speed: About 17 km per second relative to the Sun, about 3.5 AU a year
Distance from Earth in light-hours: Nearly 24 light-hours; it reaches one full light-day on 18 November 2026
Planets visited: Jupiter (5 March 1979) and Saturn (12 November 1980)
Entered interstellar space: 25 August 2012, at about 121 AU, but still inside the solar system
Power source: Three radioisotope thermoelectric generators, losing about 4 watts a year
Expected end of mission: Contact possible until about 2036, depending on remaining power
Instruments still working: Two: the magnetometer and the plasma wave subsystem (as of August 2026)
Golden Record: 30 cm gold-plated copper disc: 115 images, sounds, 90 minutes of music, 55 languages
Antenna: 3.7 metres across, pointed at Earth
Mass: 721.9 kg (NASA's figure for the spacecraft)

About Voyager 1

Voyager 1 is a spacecraft. It has no people on board. It left Earth almost fifty years ago. It flew past Jupiter. It flew past Saturn too. It took photos of their moons. Then it kept on going. Now it is very, very far away. It is the farthest thing people have made. It still sends tiny messages home. The messages take nearly a day to arrive. Voyager 1 carries a golden record. The record has songs and hellos from Earth. It is a gift for anyone out there.

Voyager 1 is a robot spacecraft launched by NASA on 5 September 1977. It flew past Jupiter in 1979 and past Saturn in 1980. Each planet's gravity gave the spacecraft a swing, speeding it on its way. At Jupiter it photographed erupting volcanoes on the moon Io.

At Saturn it studied the thick orange atmosphere of the moon Titan. After Saturn, Voyager 1 climbed away from the plane where the planets orbit. It is now the most distant object that humans have ever built. In August 2012 it crossed into interstellar space, the gap between the stars.

It has not left the solar system, because the Oort Cloud lies far beyond. Today it is about 171 times farther from the Sun than Earth is. It travels at about 17 kilometres every second. A radio message from Voyager 1 takes nearly 24 hours to reach Earth.

The spacecraft is powered by the heat of slowly decaying plutonium. That power shrinks a little every year, so instruments are switched off one by one. Bolted to its side is a golden record of music, sounds and greetings. It is a message for anyone who might find it one day.

Voyager 1 launched from Cape Canaveral on 5 September 1977 aboard a Titan IIIE-Centaur, shortly after its twin, Voyager 2, but on a faster trajectory. It made its closest approach to Jupiter on 5 March 1979, at about 280,000 km, and to Saturn on 12 November 1980, at about 126,000 km. Its Jupiter images revealed active volcanoes on Io. At Saturn, mission planners chose a close pass of Titan, at about 6,490 km, to study its dense nitrogen atmosphere; that choice bent the trajectory up and out of the plane of the planets, so Voyager 1 visited no further worlds. Uranus and Neptune were left to Voyager 2.

On 14 February 1990, about 6 billion km from home, Voyager 1 turned its cameras back for the family portrait that includes the Pale Blue Dot image of Earth. The cameras were then switched off to save power. On 17 February 1998 it overtook Pioneer 10 to become the most distant human-made object.

On 25 August 2012 Voyager 1 crossed the heliopause, the boundary where the Sun's outflowing plasma gives way to the interstellar medium, at about 121 AU. It is often reported to have left the solar system; it has not. The Sun's gravity still dominates, and the Oort Cloud, the solar system's outer reservoir of comets, lies roughly 300 years of travel ahead and would take some 30,000 years to cross.

As of August 2026, Voyager 1 is about 171 AU from Earth, moving at about 17 km/s relative to the Sun, or about 3.5 AU a year. Its radio signals take nearly 24 hours to arrive, and NASA expects it to pass one light-day from Earth on 18 November 2026. Power comes from three radioisotope thermoelectric generators fuelled by plutonium-238, which produced about 470 W at launch and lose about 4 W a year. NASA has been switching instruments off to stretch the remaining power: the cosmic ray subsystem in February 2025 and the low-energy charged particle instrument in April 2026, leaving the magnetometer and plasma wave subsystem operating. Engineers hope to keep contact through the Deep Space Network until about 2036.

Each Voyager carries a Golden Record, a 30 cm gold-plated copper disc assembled by a committee chaired by Carl Sagan, holding 115 images, natural sounds, about 90 minutes of music and greetings in 55 languages.

Did you know?

Voyager 1's computers handle about 8,000 instructions per second. A modern phone manages billions, yet Voyager still works after almost fifty years in space.
The Golden Record's cover carries a tiny sample of uranium-238, so any finder could work out the record's age from how much has decayed.
Voyager 1 will take about 300 years just to reach the inner edge of the Oort Cloud, and roughly 30,000 years to fly all the way through it.

Questions children ask

Has Voyager 1 left the solar system?

No. On 25 August 2012 it crossed the heliopause and entered interstellar space, where the Sun's wind gives way to gas between the stars. But the Sun's gravity still holds it, and the Oort Cloud of comets lies hundreds of years of travel ahead.

Can we still talk to Voyager 1?

Yes. NASA's Deep Space Network sends commands and listens for its faint replies with huge dish antennas. A message takes nearly 24 hours to travel one way, so a question and answer take almost two days.

Why did Voyager 1 not visit Uranus and Neptune?

Scientists chose a close flyby of Saturn's moon Titan in 1980 to study its thick atmosphere. That path flung Voyager 1 up and out of the plane of the planets. Voyager 2 went on to Uranus and Neptune instead.

What happens when the power runs out?

The generators lose about 4 watts each year, so NASA switches instruments off one at a time. Around 2036 there may not be enough power to send a signal. Voyager 1 will then drift on silently, still carrying its Golden Record.

Quick quiz

Three questions for space cadets. Nothing is recorded.

Which two planets did Voyager 1 fly past?
What is the Golden Record?
About how long does a radio signal from Voyager 1 take to reach Earth?

Where next?

Voyager 2

Saturn

Jupiter

Written by Anthony (A.Z. Storyworks). Facts checked against NASA Science and JPL, September 2026. Moon counts as of September 2026.

Sources