Living Titan

4. The Seas on Titan
* are methane
* why ON TITAN liquid methane is highly transparent instead of dark (Huygens MRI & HRI even looked into the sea and saw what's there!)
* waves & 'cat scratches'
* theoretical tidal forces on Titan
* atmospheric tides
* no major oceans, but shallow methane seas almost ring the equator
* tidal forces and tidal flows dictate the equatorial geography of the seas and the channels that connect them
* Will Cassini view any one sea at 0º, 90º, 180º or 270º longitude with hi-rez close-ups for comparison of sea levels at apoapsis and periapsis as independent evidence of tides and seas?
* a probable clockwise tidal circulation pattern between the North and South Saturn-facing seas ("The H"), creating two "deltas"

Huygens's landing Site

* Explores how all the instrument readings support (or don't contradict) the visually evident landing in a few cm or inches of very clear liquid methane at a mud or silt bar, and how many of the Huygens images show clearly that the sea they view could only be liquid.
* Time lapse and still images of tide pools and other water scenes in color and-or monochrome, regular and contrast expanded, showing the similarities between Huygens images and images of water on Earth.
* Mosaics showing Huygens' point of landing
* The correlation of features from HRI high altitude and SLI low altitude images.

Since its discovery by Christiaan Huygens in 1655, Titan has been a world mysterious to us. Not only its distance but its perpetual cloud layer has hidden its surface from both earthly eyes and space probe cameras. Now the Cassini mission to Saturn and the Huygens Titan lander have dimly lifted the veil and shown Titan to be a more interesting and exciting Planet than anybody imagined!

In some ways, Titan is remarkably Earthlike, and in others, very strange to us. Owing to the methane vapor in the atmosphere, which absorbs many light wavelengths visible to human eyes, on Titan we would see sunlight and shadows dimly, and we'd miss the stars at night, and perhaps even beautiful Saturn which Titan orbits. Eyes of Titanian creatures, however, would evolve to see in the wavelengths methane is transparent to, and would be able to see these sights. Titan has both land and sea areas as does the Earth. The land areas have mountains, hills and lakes. The sea areas are sculpted by the stong tides, and have sand and mud bars, tidal flats and shoals, as well as deeper areas where huge waves crawl lazily along, stirred by gentle tidal winds and superrotational breezes in the low gravity. Where Huygens landed, it was raining a drizzely rain of liquid methane, but it is not known yet whether it rains everywhere or just some places, or whether it rains all the time or just once in a while. Occasional rain clouds form and then vanish in the antarctic, where it has been summer for several Earth years as I write.

(It seems obvious from Cassini and Huygens images and other observations that) Titan is covered with verdant vegetation. Forests with plants and trees of sizes exceeding anything ever seen on Earth poke their way upward in the low gravity and calm weather. The forests extend from the tropics into the high arctic and the vegetation changes in character with the latitude. The seas and lakes are filled with aquatic vegatation much in the nature of gigantic swamps. Gigantic vines with sessile leaves crawl for kilometers across the mud bars and over the sea. With the cold temperature, the low gravity, and the long seasons, all of this vegetation probably lives very much in slow motion compared to life on Earth. The individual forest plants may perhaps be but little changed since Columbus ventured to the Americas on Earth.

The only possible signs of animal life so far are dubious at best. However, most of the views were too distant to identify animals unless they were colossal - "Titanic".

Earth has two poles: North and South. Titan has four: North, South, Saturn and Anti-Saturn. Along the equator, tidal flows rush back and forth between the Saturn -- anti-Saturn seas and the mid-longitude seas at right angles to Saturn over the course of each Titanian day, 16 Earth days long. The time of day of the tide changes slowly over the course of the year, 30 Earth years long. Titan's 'water' is liquid methane (CH4): at Titan's 94 degree Kelvin temperatures, Earth's water (H2O ice) is just another kind of rock.

The atmosphere is just a little thicker than the Earth's (Huygens measured 1460 millibars) and composed mainly of the same gas, nitrogen. It is the only other world in the solar system with an air pressure even remotely similar to Earth's. Oxygen, however, is absent, and water vapour is replaced by methane vapour.

Titan's gravity is only about 1/7 of the Earth's. This is even less than our moon's gravity (1/6) even though Titan is over three times the size of our moon, because Titan's core contains many lighter materials such as ice, and so it is less dense. The horizon would seem strangely close to us owing to Titan's smaller size. Although Titan is just 1/15th of Earth's size by volume, it has 1/6 of its surface area.

While there is a lot more of Titan unexplored than explored, it would appear that much of tropical Titan could be likened to a vast swampy wetlands, where the question about the almost flat surface is not always "liquid or land?" but "how soggy?"

Titan Revealed!, at a methane-transparent wavelength (939 nm)
Center is 15º south and 156º west; Huygens landed at 10º S, 192º W.
The dark area is the Saturn antipodal sea -- Saturn is never seen on Titan from this hemisphere, while from the other, it always sits at one point in the sky, lighting the nights. There appear to be shallows to the East of the islands, possibly silt in the lee of tidal flows. The bright "sinewy" region to the East of it has been dubbed "Xanadu". Clouds are seen near the South pole, which were gone on the next fly-by, probably having rained in the polar region. Some of the darker features here and there are lakes, and what seem to be mountains have been seen in the southern mid latitudes.

[Panorama Image]

A tropical methane sea as seen by the descending Huygens lander. What looked like an island with rivers from high altitude looks more and more like a flat mudbar, awash in the sea and covered with huge plants, as Huygens nears its landing on another, very small, mudbar. The dark "rivers" are seen as being shadows and reflections of the leaves and stems. Aquatic vegetation appears in and floats on the deeper area in front of the mudbar. The transparency of the methane and the similar chemistry of air and sea may explain Titan's prolific aquatic vegetation, which appears in Cassini images to blanket almost the whole of the seas, like duckweed, bullrushes, water lillies and so on on an Earthly pond.
The area behind the mudbar is probably a very immense, flat beach, just submerged, with big waves slowly rolling in over it. However, I've never been entirely certain these are waves and not gigantic floating plant stems -- I colored some as such. These are also seen by Cassini's radar and labelled "sand dunes", but they are not seen in the visual images.
It seems it was raining at the time of the landing, with drops of methane almost 1/2 inch across lazily drizzling down from the gold-orange sky and making the view hazy. In nearly all the images, considerable contrast enhancement has been employed to attempt to discern detail in what was dimly seen through the rain or drifting about submerged in the clear sea.

Size	5156 Km Diameter; somewhat larger than Mercury; almost half the size of Mars; 1/15 the size of Earth (by volume). The total surface area is 16% of Earth's, or 3/5 of our Land area, or 83 million square Km.
Density	1.8 - about twice that of water. (Earth, the densest planet, is about 5.5.)
Atmosphere	1460 mBars or 21 PSI as measured by Huygens at sea level, 4.5 times as dense as Earth's air. (from Boyle's law of boiling: gas density=pressure/temperature, =1.46 bars / (93K/295K). ) Extends over 1000 Km into space. (Cassini dares not fly much closer!) ~95% Nitrogen, 5% Methane vapour.
Seas	Liquid Methane (CH4). Strong tidal flows on a once-per-Titan-day cycle. (See The Seas on Titan)
Daytime Surface Temperature	93.65 +/- .25 degrees Kelvin, or -187 degrees Celsius as measured by Huygens at the surface. This is 1/3 the thermal energy of Earth.
Distance from Saturn	1.2 Gm (Giga-meters), slightly elliptical causing tides; Earth's moon is .4 Gm from Earth
Length of day	16 Earth days; Titan orbits gas-giant Saturn once in that time, and keeps the same face always towards Saturn.
Distance from Sun	1400 Gm (Giga-meters); Earth is 150 Gm
Year	30 Earth Years; Titan is 9.5 times as far from the sun as Earth
Inclination of Equator to the Sun (Seasons)	26-3/4 degrees (same as Saturn's rings); Earth 23-1/2 degrees

Foreword: ABOUT LIVING TITAN WEBSITE

My Titan studies started in March (2005) with disbelief of the astonishing idea that Huygens saw no liquid methane, when it is ubiquitous in the images and also was apparently detected by the downward looking spectrometers from 21 meters altitude and by the GCMS instrument when Huygens's landed "with a splat". The Huygens images now appear to have been cast aside with little attention ever having been paid to their fascinating content.

It is tedious to discern the features of a scene and easy to read things that aren't really there into low-resolution monochrome images, degraded by "dewdrops" on the lenses and lossy image compression. However, the Huygens images and data, collected at great expense and effort from on Titan itself, are of adequate quality to reliably show Most Interesting Real scenes. Finer points of detail are often ambiguous for the very reason of what they show: a changing seascape with features in or on very shallow liquid. Many features are seen several times as Huygens descends, providing independent checks of each other to illuminate truth and separate it from illusions of light and shadow. Applicable Cassini images also very much correspond with Huygens images and support the model presented. In fact, no instrument readings or images I've been able to find actually contradict the views herein expressed: even with observations that appear to contradict each other such as the Earth-based 2003 radar versus the 2005 IR checks for reflections from liquid, this scenario appears to explain why they might.

Welcome to Living Titanweb site

by Craig Carmichael, independent researcher