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50 free Titan (Moon) trivia questions with answers — science & nature quiz, new questions added Aug 2026.
Titan is the moon that behaves like a planet. Bigger than Mercury, wrapped in an atmosphere denser than Earth's, and the only world besides our own with lakes and seas on its surface, it hides under an orange smog so thick that nobody saw the ground until the Huygens probe dropped through it in January 2005 and photographed ice pebbles on a dark plain. These 50 questions cover Christiaan Huygens' discovery in 1655, John Herschel's naming, the 16-day orbit and synchronous rotation, the Voyager flyby that demoted Titan from largest moon to second-largest, the Cassini-Huygens mission and its radar maps, the nitrogen and methane atmosphere, the 94-kelvin surface, the methane cycle that mimics Earth's water cycle, Kraken and Ligeia Mare, the dune fields and the Australia-sized bright region Xanadu, candidate cryovolcanoes like Doom Mons, the Argon-40 clue, the Hubert Curien Memorial Station, and the proposed submarines, boats and balloons that never flew. The easy tier asks which planet Titan orbits; the expert tier wants the orbital resonance with Hyperion and the name of the hypothetical methane-based cell membrane. Every answer is cited to a page we checked and comes with a short explanation. Play it solo or print it for a science-club night.
30 of 50 questions with answers and explanations. Play the quiz
Q 01Which moon is the only one in the Solar System larger than Titan?
Ganymede
Titan was thought to be bigger until Voyager 1 showed its haze had inflated its apparent size.
Q 02Titan is larger than which planet?
Mercury
Despite the size, Titan has only 40% of that planet's mass because it is mostly ice.
Q 03Who discovered Titan in 1655?
Christiaan Huygens
The Dutch astronomer built his own telescopes with his elder brother Constantijn.
Q 04What Latin name did its discoverer give Titan?
Saturni Luna
He published the find in the tract De Saturni Luna Observatio Nova.
Q 05Who gave Titan its name in 1847?
John Herschel
He named all seven then-known Saturnian moons after mythological giants.
Q 06What Roman numeral does the IAU give Titan in Saturn's moon list?
VI
Early astronomers had called it Saturn IV, before more inner moons were found.
Q 07Titan was the how-many-th known planetary satellite?
Sixth
It followed Earth's moon and the four Galilean moons of Jupiter.
Q 08Roughly how long does Titan take to orbit Saturn?
16 days
Precisely 15 days and 22 hours; because it is tidally locked, its day is the same length.
Q 09Which small, irregular moon is locked in a 3:4 orbital resonance with Titan?
Hyperion
It orbits three times for every four Titan orbits and may have formed from debris of a collision with Titan.
Q 10What is Titan's diameter, to the nearest hundred kilometres?
5,100 km
That makes it 6% wider than Mercury and 50% wider than Earth's Moon.
Q 11Which spacecraft's 1980 visit revealed Titan was not the Solar System's largest moon?
Voyager 1
Its haze layer, 100-200 km above the surface, had inflated the apparent diameter.
Q 12What is Titan's surface atmospheric pressure compared with Earth's?
About 1.45 times
It is the only moon with an atmosphere denser than Earth's.
Q 13Which other moon, besides Titan, has an atmosphere that supports clouds and weather?
Triton
Neptune's big moon is the only other with hazes and weather.
Q 14Who first suspected Titan had an atmosphere after seeing limb darkening?
Q 21What is Titan's approximate surface temperature?
94 K
That is about minus 179 Celsius, cold enough to keep water ice rock-hard.
Q 22What fraction of Earth's sunlight actually reaches Titan's surface?
About 0.1%
Titan gets 1% as much sunlight as Earth, and the atmosphere absorbs 90% of that.
Q 23What does Titan's haze produce by absorbing sunlight before it reaches the ground?
An anti-greenhouse effect
By absorbing sunlight it leaves the surface much colder than the upper atmosphere.
What is the large, bright equatorial region on Titan about the size of Australia called?
Josep Comas i Sola
Kuiper confirmed a methane atmosphere spectroscopically in 1944.
Q 15Which gas makes up around 95-98% of Titan's atmosphere?
Nitrogen
Methane is second at a few percent, and hydrogen third at roughly 0.1%.
Q 16What is the methane concentration Huygens measured near Titan's surface?
4.92%
It stays roughly constant up to 8 km and falls to 1.41% in the stratosphere.
Q 17What colour is the smog that hydrocarbon reactions create in Titan's upper atmosphere?
Orange
Sunlight breaks up methane and the fragments recombine into heavier hydrocarbons.
Q 18Within how long should sunlight have destroyed all of Titan's atmospheric methane?
50 million years
That implies a reservoir inside Titan keeps topping it up, possibly via cryovolcanoes.
Q 19What are the complex organic chemicals thought to form in Titan's atmosphere called?
Tholins
NASA reported in 2013 that simulations of Titan's atmosphere produced them.
Q 20Which hydrocarbon did Cassini detect on Titan in 2013, a first beyond Earth?
Propene
It was also the first chemical found by the composite infrared spectrometer.
Xanadu
Hubble first spotted it in infrared images in 1994.
Q 25What is the name of Titan's largest sea?
Kraken Mare
It sits near the north pole with the other two great seas, which together cover about 691,000 square km.
Q 26What is the measured maximum depth of Ligeia Mare?
About 200 metres
Cassini radar bathymetry used subsurface reflections; Ontario Lacus is about 90 metres deep.
Q 27Where on Titan are almost all of its lakes and seas found?
The polar regions
Colder temperatures there allow permanent liquid hydrocarbons; the south pole has four dry depressions.
Q 28In which month and year did the Cassini team announce definitive evidence of methane lakes?
January 2007
Hubble and radar had hinted at hydrocarbon seas as early as 1995.
Q 29How tall is the permanent tidal bulge at Titan's sub- and anti-Saturn points?
About 100 metres
The tidal range of the major seas is only around 0.2 to 0.8 metres.
Q 30Which two mountains form part of Titan's likeliest cryovolcanic complex?
Doom Mons and Erebor Mons
The complex also includes the depression Sotra Patera and the flow-like Mohini Fluctus.