50 Fun Facts About Titan (Moon)

Which moon is the only one in the Solar System larger than Titan?

Titan was thought to be bigger until Voyager 1 showed its haze had inflated its apparent size.

Titan is larger than which planet?

Despite the size, Titan has only 40% of that planet's mass because it is mostly ice.

Who discovered Titan in 1655?

The Dutch astronomer built his own telescopes with his elder brother Constantijn.

What Latin name did its discoverer give Titan?

He published the find in the tract De Saturni Luna Observatio Nova.

Who gave Titan its name in 1847?

He named all seven then-known Saturnian moons after mythological giants.

What Roman numeral does the IAU give Titan in Saturn's moon list?

Early astronomers had called it Saturn IV, before more inner moons were found.

Titan was the how-many-th known planetary satellite?

It followed Earth's moon and the four Galilean moons of Jupiter.

Roughly how long does Titan take to orbit Saturn?

Precisely 15 days and 22 hours; because it is tidally locked, its day is the same length.

Which small, irregular moon is locked in a 3:4 orbital resonance with Titan?

It orbits three times for every four Titan orbits and may have formed from debris of a collision with Titan.

What is Titan's diameter, to the nearest hundred kilometres?

That makes it 6% wider than Mercury and 50% wider than Earth's Moon.

Which spacecraft's 1980 visit revealed Titan was not the Solar System's largest moon?

Its haze layer, 100-200 km above the surface, had inflated the apparent diameter.

What is Titan's surface atmospheric pressure compared with Earth's?

It is the only moon with an atmosphere denser than Earth's.

Which other moon, besides Titan, has an atmosphere that supports clouds and weather?

Neptune's big moon is the only other with hazes and weather.

Who first suspected Titan had an atmosphere after seeing limb darkening?

Kuiper confirmed a methane atmosphere spectroscopically in 1944.

Which gas makes up around 95-98% of Titan's atmosphere?

Methane is second at a few percent, and hydrogen third at roughly 0.1%.

What is the methane concentration Huygens measured near Titan's surface?

It stays roughly constant up to 8 km and falls to 1.41% in the stratosphere.

What colour is the smog that hydrocarbon reactions create in Titan's upper atmosphere?

Sunlight breaks up methane and the fragments recombine into heavier hydrocarbons.

Within how long should sunlight have destroyed all of Titan's atmospheric methane?

That implies a reservoir inside Titan keeps topping it up, possibly via cryovolcanoes.

What are the complex organic chemicals thought to form in Titan's atmosphere called?

NASA reported in 2013 that simulations of Titan's atmosphere produced them.

Which hydrocarbon did Cassini detect on Titan in 2013, a first beyond Earth?

It was also the first chemical found by the composite infrared spectrometer.

What is Titan's approximate surface temperature?

That is about minus 179 Celsius, cold enough to keep water ice rock-hard.

What fraction of Earth's sunlight actually reaches Titan's surface?

Titan gets 1% as much sunlight as Earth, and the atmosphere absorbs 90% of that.

What does Titan's haze produce by absorbing sunlight before it reaches the ground?

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?

Hubble first spotted it in infrared images in 1994.

What is the name of Titan's largest sea?

It sits near the north pole with the other two great seas, which together cover about 691,000 square km.

What is the measured maximum depth of Ligeia Mare?

Cassini radar bathymetry used subsurface reflections; Ontario Lacus is about 90 metres deep.

Where on Titan are almost all of its lakes and seas found?

Colder temperatures there allow permanent liquid hydrocarbons; the south pole has four dry depressions.

In which month and year did the Cassini team announce definitive evidence of methane lakes?

Hubble and radar had hinted at hydrocarbon seas as early as 1995.

How tall is the permanent tidal bulge at Titan's sub- and anti-Saturn points?

The tidal range of the major seas is only around 0.2 to 0.8 metres.

Which two mountains form part of Titan's likeliest cryovolcanic complex?

The complex also includes the depression Sotra Patera and the flow-like Mohini Fluctus.

Which isotope in Titan's atmosphere is indirect evidence for active geology?

It comes from potassium-40 decaying in the rocky core and must somehow reach the surface.

Titan's dunes are concentrated within how many degrees of the equator?

Sand there is mostly organic material, transported generally west to east.

In which direction is sand generally transported across Titan's dune fields?

Dune interactions with obstacles such as mountains reveal the direction.

Why are Titan's craters mostly found in equatorial dune fields rather than at the poles?

Erosion and burial are the main ways Titan's shallow craters get modified.

Which probe, in 1979, was the first to visit the Saturn system?

It suggested Titan was probably too cold to support life.

Which two space agencies jointly ran the Cassini-Huygens mission?

The orbiter reached Saturn on July 1, 2004 and began mapping Titan by radar.

On what date did the Huygens probe touch down on Titan?

Titan remains the most distant body from Earth to have had a probe land on it.

The Huygens landing site was named as a memorial station to whom?

He was a former president of the European Space Agency.

What were the small rocks and pebbles photographed by Huygens made of?

The hills nearby are also mainly water ice, with dark organics washed down by methane rain.

The Huygens probe landed just off the tip of which bright region?

It photographed pale hills with dark rivers running to a dark plain.

How close was Cassini's closest flyby of Titan, in June 2010?

The first targeted close flyby, in July 2006, was at 950 km.

What kind of vehicle is NASA's Dragonfly mission designed to fly on Titan?

Built by Johns Hopkins APL and powered by an RTG, it was scheduled to launch in July 2028.

The Titan Saturn System Mission proposed floating what in Titan's atmosphere?

It lost out to the Europa Jupiter System Mission for funding priority in 2009.

In 2015 NASA's NIAC programme funded a study of what kind of Titan explorer?

The Phase II grant went to a design for exploring Titan's seas.

What would hypothetical methane-lake life on Titan breathe in instead of oxygen?

It would metabolise it with acetylene rather than glucose and exhale methane.

What name was given to a hypothetical cell membrane that could work in liquid methane?

It combines azote, French for nitrogen, with liposome.

Which astrobiologist argued in 2005 that methanogenic life would alter Titan's troposphere?

In 2010 Strobel's data showed hydrogen flowing downward and vanishing near the surface, though non-biological explanations are likelier.

In about five billion years, what could make Titan's surface habitable?

Warming could allow liquid water on the surface for several hundred million years.

Titan is the only moon known to have what?

Its air is denser than Earth's, and it is the only world besides Earth with stable surface liquid.

Why does Titan always show the same face to Saturn?

Its rotation period therefore equals its orbital period of just under 16 days.