Hugo's Solar System
Spacecraft
Voyager 2
The only spacecraft to visit all four giant planets, now sailing between the stars
Key facts
- Launched
- 20 August 1977, Cape Canaveral, on a Titan IIIE-Centaur rocket
- Where it is now
- About 144 AU from the Sun (roughly 13.4 billion miles / 21.5 billion km) on 8 September 2026
- Speed
- About 15.4 km/s relative to the Sun (about 3.1 AU per year)
- Distance from Earth
- About 143 AU; nearly 20 light-hours away on 8 September 2026
- Planets visited
- Jupiter (1979), Saturn (1981), Uranus (1986), Neptune (1989)
- Entered interstellar space
- 5 November 2018, at about 119.7 AU
- Power source
- Three plutonium radioisotope thermoelectric generators, losing about 4 watts a year
- Expected end of mission
- Instruments are being switched off one by one; contact may last into the mid-2030s
- Instruments still working
- Three of eleven as of April 2026 (cosmic ray, magnetometer, plasma wave); the cosmic ray subsystem is due to be switched off in 2026
- Golden Record
- 30 cm gold-plated copper disc with images, music and greetings in 55 languages
- Launch mass
- 721.9 kg
About Voyager 2
Voyager 2 is a spacecraft. It has no people on board. It left Earth almost fifty years ago. It flew past four giant planets. It saw Jupiter and Saturn. Then it saw Uranus and Neptune. No other spacecraft has been to those two. It took thousands of pictures. Now it is far, far away. It is past all the planets. It is still flying today. It still talks to Earth. Its voice takes twenty hours to reach us. Voyager 2 carries a golden record. The record has music and hello in many tongues. It is a gift for anyone who finds it.
Voyager 2 is a robot spacecraft that left Earth on 20 August 1977. It is the only spacecraft ever to visit all four giant planets. It flew past Jupiter in 1979 and Saturn in 1981. Then it reached Uranus in 1986 and Neptune in 1989.
No other spacecraft has visited Uranus or Neptune since. At each planet, the planet's gravity bent its path and sped it up. This trick, called a gravity assist, let one spacecraft visit four worlds. Voyager 2 found new moons and rings at every planet it passed.
It measured winds in Neptune's atmosphere at about 1,100 kilometres per hour. It also found that Uranus rotates on an axis tipped almost on its side. Today Voyager 2 is about 144 AU from the Sun, or 21 billion kilometres. It travels at about 15 kilometres per second and still sends data home.
Its radio signal takes nearly 20 hours to reach Earth. In November 2018 it crossed into interstellar space, beyond the Sun's wind bubble. Three plutonium-powered generators power it, but they lose about 4 watts each year. Engineers switch off instruments one by one to save power.
Like its twin Voyager 1, it carries a golden record from Earth.
Voyager 2 launched on 20 August 1977 from Cape Canaveral on a Titan IIIE-Centaur rocket, sixteen days before its twin, Voyager 1. The numbering reflects the order in which they reached Jupiter, not the launch order: Voyager 1 took a faster route and overtook its sibling on 15 December 1977. Each spacecraft has a launch mass of 721.9 kg and carries eleven scientific instruments.
Voyager 2 remains the only spacecraft to have flown past all four giant planets, using a gravity assist at each to reach the next. It passed Jupiter on 9 July 1979 at about 645,000 km, Saturn on 26 August 1981 at about 101,000 km, Uranus on 24 January 1986 at about 81,500 km and Neptune on 25 August 1989 at about 4,800 km. Along the way it discovered one new moon at Jupiter, about ten at Uranus and six at Neptune, found new rings at Uranus and Neptune, measured winds of about 1,100 km/h in Neptune's atmosphere and mapped the strangely tilted magnetic fields of the two ice giants.
On 5 November 2018 Voyager 2 crossed the heliopause, the boundary where the solar wind gives way to the interstellar medium, at about 119.7 AU. It is often said that the Voyagers have left the solar system. They have not: the Sun's gravity still dominates, and the Oort Cloud begins at roughly 1,000 AU. NASA estimates about 300 years to reach the Oort Cloud's inner edge and perhaps 30,000 years to pass through it.
On 8 September 2026, JPL Horizons places Voyager 2 about 143.9 AU from the Sun and 143.4 AU from Earth, a one-way light time of nearly 20 hours. It is travelling at about 15.4 km/s relative to the Sun, roughly 3.1 AU per year. Power comes from three radioisotope thermoelectric generators whose output falls by about 4 watts each year; NASA has been switching off instruments in turn, and as of April 2026 three remained active (cosmic ray, magnetometer and plasma wave), with the cosmic ray subsystem scheduled to be switched off during 2026. Engineering contact could last into the mid-2030s. Like Voyager 1, it carries a Golden Record, a 30 cm gold-plated copper disc of images, music and greetings in 55 languages, assembled by a committee chaired by Carl Sagan.
Did you know?
- Voyager 2 launched sixteen days before Voyager 1, but its twin took a faster route and overtook it on 15 December 1977.
- Voyager 2 is still the only spacecraft ever to visit Uranus and Neptune, and no other mission has been back since 1989.
- The spacecraft were built to last five years, yet Voyager 2 is still sending data home almost fifty years after launch.
Questions children ask
Has Voyager 2 left the solar system?
Not yet. In November 2018 it crossed the heliopause, where the Sun's wind stops, so it is in interstellar space. But the Sun's gravity still holds it, and the Oort Cloud lies far ahead. NASA thinks it will take about 300 years to reach the Oort Cloud's inner edge.
How does Voyager 2 talk to Earth from so far away?
It sends a very faint radio signal to huge dish antennas on Earth called the Deep Space Network. The signal travels at the speed of light, yet it still takes nearly 20 hours to arrive, because Voyager 2 is about 143 AU from Earth.
Why is it called Voyager 2 if it launched first?
The two spacecraft were numbered by the order they would reach Jupiter, not by launch date. Voyager 1 took a shorter, faster path and overtook Voyager 2 in December 1977, arriving at Jupiter four months earlier.
When will Voyager 2 stop working?
Its three nuclear power generators lose about 4 watts every year, so engineers switch off instruments one at a time to save power. In early 2026 three instruments were still working, with one more due to be switched off during the year. NASA hopes to stay in contact into the mid-2030s, when the power will finally run too low.
Quick quiz
Three questions for space cadets. Nothing is recorded.
- Which two planets has only Voyager 2 ever visited?
- In which year did Voyager 2 launch from Earth?
- What powers Voyager 2 so far from the Sun?
Where next?
Voyager 1
Neptune
UranusSources
- https://science.nasa.gov/mission/voyager/voyager-2/
- https://science.nasa.gov/mission/voyager/where-are-they-now/
- https://science.nasa.gov/mission/voyager/voyager-1/
- https://science.nasa.gov/mission/voyager/
- https://science.nasa.gov/mission/voyager/frequently-asked-questions/
- https://science.nasa.gov/mission/voyager/voyager-golden-record-overview/
- https://www.jpl.nasa.gov/missions/voyager-2/
- https://www.jpl.nasa.gov/news/nasas-voyager-2-probe-enters-interstellar-space/
- https://ssd.jpl.nasa.gov/api/horizons.api
- https://en.wikipedia.org/wiki/Voyager_2
- https://en.wikipedia.org/wiki/Voyager_Golden_Record