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50 free Voyager Missions trivia questions with answers — science & nature quiz, new questions added Aug 2026.
Two spacecraft launched in the summer of 1977 are still phoning home from beyond the edge of the Sun's influence, running on plutonium, 1970s computers and a data rate slower than a dial-up modem. The Voyagers were meant to last a decade. They found volcanoes on Io, rings around Jupiter, a haze-choked Titan, eleven new moons at Uranus and a Great Dark Spot on Neptune, then turned around and photographed Earth as a pale blue dot. These 50 questions follow both probes from the rare planetary alignment that Gary Flandro spotted in 1964 through the cancelled Grand Tour, the Mariner 11 and 12 names they nearly kept, the Titan IIIE launches and the near-failure that almost stranded Voyager 1. There are questions on the Jupiter and Saturn encounters, why Voyager 1 gave up Pluto for Titan, the 3.7-metre dish, the heliopause crossings of 2012 and 2018, the bad memory chip of 2023, and the stars the probes will drift past in 40,000 years. Easy questions stick to launch years and planets; the hard tier asks about plated-wire memory, the Centaur stage's 3.4-second margin and which Canberra dish is the only one that can reach Voyager 2. Every answer is cited to a page we checked, with a short explanation so you learn something either way.
30 of 50 questions with answers and explanations. Play the quiz
Q 01In which year were both Voyager probes launched?
1977
They took advantage of a rare alignment that let one craft reach all the outer planets with gravity assists.
Q 02Which probe was launched first?
Voyager 2
Voyager 1 followed 16 days later on a shorter, faster path and still reached Jupiter first.
Q 03On what date was Voyager 1 launched?
September 5, 1977
It lifted off from Launch Complex 41 at Cape Canaveral aboard a Titan IIIE.
Q 04Which rocket launched the Voyager probes?
Titan IIIE
A Centaur upper stage rode on top and had to burn far longer than planned to rescue Voyager 1's launch.
Q 05How close to running dry was the Centaur stage when it saved Voyager 1's launch?
3.4 seconds of propellant
The Titan's second stage shut down early and left 540 kg of fuel unburned; the Centaur made up the difference.
Q 06Which JPL engineer identified the once-in-175-years alignment behind the Grand Tour in 1964?
Gary Flandro
The Grand Tour itself was cancelled in 1971 when money went to the Space Shuttle.
Q 07Why was the original Grand Tour mission cancelled in December 1971?
Funding went to the Space Shuttle
A scaled-down two-spacecraft, four-planet version was proposed the next year.
Q 08What were the Voyagers originally going to be called?
Mariner 11 and 12
The name Voyager was picked in a 1977 competition, echoing William Pickering's earlier suggestion of "Navigator".
Q 09What name had William Pickering earlier proposed that the 1977 rename echoed?
Navigator
Because the change came so close to launch, the probes were still sometimes called Mariner 11 and 12.
Q 10Which moon did Voyager 1 study instead of continuing to Pluto?
Titan
Its dense atmosphere made it the priority; the flyby threw Voyager 1 out of the ecliptic and ended its planetary mission.
Q 11What did Voyager 1 discover on Jupiter's moon Io?
Active volcanoes
It was the first time active volcanism had been seen anywhere beyond Earth.
Q 12How many Io volcano eruptions did the two Voyagers observe between them?
Nine
Voyager 2 ran a 10-hour "volcano watch" and saw how Io's surface had changed in four months.
Q 13Which Jovian moon's lines looked as if "painted on with a felt marker"?
Europa
High-resolution Voyager 2 images showed the lines had no relief; a thin ice crust over an ocean is the leading explanation.
Q 21How many new moons of Uranus did Voyager 2 discover?
11
They include Cordelia, Ophelia, Puck and Perdita, most named for Shakespeare characters.
Q 22How long is a day on Uranus, as measured by Voyager 2?
17 hours 14 minutes
The planet's 97.8-degree axial tilt gives it a uniquely odd atmosphere and seasons.
Q 23Which Uranian moon showed huge fault canyons, suggesting it was once shattered and reassembled?
Miranda
One hypothesis is that the moon re-aggregated after being broken apart by a violent impact.
Q 24What did Voyager 2 discover in Neptune's atmosphere in 1989?
Q 14Which was the first of Jupiter's moons to be identified by a spacecraft?
Metis
Voyager 1 spotted it just outside Jupiter's ring, then found Thebe between Amalthea and Io.
Q 15What was applied to some Voyager cables shortly before launch to improve radiation shielding?
Kitchen-grade aluminium foil
Pioneer 10's data had warned engineers just how fierce Jupiter's radiation belts were.
Q 16When did Voyager 1 make its closest approach to Jupiter?
March 5, 1979
It passed about 349,000 km from the planet's centre; most moon and ring observations came in a 48-hour window.
Q 17What share of Saturn's upper atmosphere did Voyager 1 find to be helium?
About 7 percent
That is less than Jupiter's 11 percent, hinting that helium may be sinking and warming Saturn from within.
Q 18How fast were the equatorial winds the Voyagers measured on Saturn?
About 500 m/s
That is roughly 1,100 mph, far faster than anything on Earth.
Q 19Which is the only spacecraft to have visited Uranus and Neptune?
Voyager 2
It reached Uranus in 1986 and Neptune in 1989.
Q 20In which year did Voyager 2 fly past Uranus?
1986
Closest approach was on January 24, 1986, at 81,500 km above the cloud tops.
The Great Dark Spot
Hubble later found the feature had vanished; it may have been a window in the methane cloud deck.
Q 25On what date did Voyager 2 make its closest approach to Neptune?
August 25, 1989
It passed about 4,950 km above Neptune's north pole after a 1987 course correction.
Q 26Which of these moons was among the six Voyager 2 confirmed at Neptune?
Proteus
Despina, Galatea, Larissa, Proteus, Naiad and Thalassa were all confirmed; Triton and Nereid were already known.
Q 27What seized up on Voyager 2 after its Saturn flyby?
The scan platform's azimuth actuator
Worn lubricant, corrosion and a bearing design flaw were blamed; ground commands partly freed it.
Q 28What failed on Voyager 2 in 1978, leaving it able to hear only one precise frequency?
Its primary radio receiver
A bad capacitor in the backup receiver means Earth must tune commands to the Doppler shift and the receiver's temperature.
Q 29What is the diameter of each Voyager's high-gain antenna?
3.7 metres
Uplink is on S-band and downlink on X-band, with S-band as backup.
Q 30What powers the Voyager spacecraft?
Plutonium-238 generators
Three RTGs gave about 470 watts at launch, falling roughly 0.79 percent a year.