Titan: Artistic views

Titan Artistic Views

Radar Image credit: NASA/JPL-Caltech

Note: The arrow was incorporated into the radar portion showing the weird bay of Ontario Lacus to indicate the area represented in the artistic image.

The computer-generated image, in the upper part of the table above, unveils a surprising bay in the eastern shoreline of the largest pool of liquids in the south polar region. The kidney-shaped lake, approximately 235 km long and 15,000 square kilometers or 6,000 square miles in surface area is called Ontario Lacus. The lake is, probably, mainly composed of methane, ethane and propane.
The artistic view is based on a radar image obtained by the radar mapper of the Cassini probe on January 12, 2010. The radar image in the lower left part of the table above shows the global view of Ontario Lacus. The radar image in the lower right part of the table corresponds to an enlargement of the area where the intriguing bay represented in the artistic image is located. The gray arrow shows the orientation of the virtual camera.
The intriguing bay marks a rupture in the eastern coastline of Ontario Lacus which appears relatively regular and linear. How did this bay form? Its origin is uncertain. The bay seems different in nature from a bay in the western shoreline where an apparent fluvial activity can account for its formation through sedimentary accumulations.
The bay appears to take shape in a deep topographic depression because the radar signature of the liquid is particularly dark and uniform. A sharp topographic incision into the coast can be clearly observed suggesting a potential collapse of the elevated terrain. One can wonder whether the eastern coast is not floating on a subsurface layer of liquids. Infiltration processes into a relatively porous ground may be at work in that area.
The intriguing bay may have been formed by a meteoritic impact generating a big topographic depression, as well. Or does this bay represent a volcanic caldera? Further studies regarding bathymetry or absorptivity of the liquid are needed to account for this strange feature in Ontario Lacus. And let's hope that the lake, which appears to be drying up, will stop evaporating as the autumn season advances in the southern hemisphere.

Image Credit: NASA/JPL

Note: The arrow was incorporated into the radar portion showing the delta of Mezzoramia to indicate the area represented in the artistic image.

The « artistic » simulation view, above the radar images taken with the radar mapper of the Cassini spacecraft, represents a delta or estuary of Mezzoramia, an optically-dark patch in the south polar region of Saturn’s largest moon ,Titan. The image shows an area located at about 73 degrees south latitude and 30 degrees west longitude.
The image was generated on the basis of a radar portion of the south-west of Mezzoramia acquired with the Synthetic Aperture Radar instrument of the Cassini spacecraft on December 20, 2007.
The radar view was first retrieved, reprocessed with a photo editor in order to partially remove the noise related to the relatively low resolution of the radar image. The portion of the radar swath was then incorporated into a landscape generator which produces landscapes depending on the brightness variations of the radar view.
The view is based on the assumption that the hills are no higher than 200 meters (600 feet).
Currently, the dark patch of Mezzoramia is thought to be partially filled with liquid methane or ethane. Since the Winter Solstice in the southern hemisphere is approaching (Winter will start in May 2017), it is likely that Mezzoramia will progressively fill with liquid hydrocarbons. The snapshot is supposed to be taken in the winter period.
The radar swath of December 20, 2007 clearly shows a dark drainage channel connected to the south-west portion of the dark Mezzoramia. This sinuous drainage channel runs southward, over a distance of about 300 km or 190 miles, to the eroded region of Sikun Labyrinthus, a complex and rugged terrain made of hills and dendritic canyons, reminiscent of karstic regions on Earth. The delta of Mezzoramia appears to be approximately 10 km or 6 miles wide.
The artistic simulation takes several parameters into account: the luminosity reaching the soil is particularly weak and the Sun is low on the horizon. Moreover, the sky is not perfectly clear due to a dense haze. The hills are dominated by reflective materials such as water ice or frozen carbon dioxide. The relatively low density of liquid methane and ethane prevents water ice from floating on that liquid.

This Titan artistic view shows one of the lakes in the surroundings of the giant south polar Lake "Ontario Lacus". The area is currently in the summer season that is about to come to an end. This extra-terrestrial pool probably consists, mostly, of liquid ethane according to the spectral analysis of latest data.
It is suspected that the evaporation process during the Titan summer is very high which implies that the level of the south polar pools is approaching its minimum in the yearly cycle of this Saturn moon. That would explain why the north polar region, currently in the winter hemisphere, appears, today, largely wetter and cloudier than the south polar region. The season changes on Titan are likely well pronounced due to the relatively high inclination angle ( over 26 degrees ) of the rotation axis of Titan to the normal of the orbital plane. Will there be hydrocarbon or cloud migrations from the north pole to the south pole in the coming years as northern winter is about to terminate ?

The computer-generated image above unveils the coastline of a bay from one of the largest bodies of liquid in Titan's north polar region. It was obtained with the landscape generator Terragen on the basis of a radar portion captured by the Cassini spacecraft during the 31st Titan flyby ( T30 ) on May 12, 2007.
The radar view on the right is the image used to produce the virtual snapshot above. The portion is centered, roughly, at 70 degrees north latitude and 310 degrees west longitude and it is about 270 km long ( around 169 miles ) by 160 km wide ( around 100 miles ). The snapshot is supposed to be taken from the arrow as shown on the radar view.
The dark area on the radar view is interpreted as a liquid area since it is uniform and dark which means that it completely ( or almost completely ) absorbs the radar signal. On the other hand, the brighter area indicates rough topographic features like hills, valleys or rivers. The brighter portions are interpreted as the higher peaks on the terrain. The landscape generator translates darker regions into lower elevation topography and brighter regions into higher elevation topography.
The radar view doesn't give any significant clue upon the height of the hills or mountains. On this artistic view, the depth of the pool along the shoreline is about 5 meters, the icy hills don't exceed 200 meters and the camera is at about 100 meters above lake level. The big lake is assumed to contain ethane molecules since a giant ethane cloud engulfing the north polar region had been identified.

Radar Image Source: NASA, JPL

The image above represents a wet area of Titan in the Saturn facing hemisphere at high latitudes towards the south pole. It is currently summer and the region is in a rainy period. It has just undergone what is comparable to a tropical storm on Earth. Due to the little amount of solar energy received, the process of cloud formation is very slow. But when the clouds reach a certain point of mass and density, they release the hydrocarbon compounds in a very sudden way as speculated Ralph Lorenz ( monsoon events). The high concentration of methane in Titan's atmosphere, especially near the soil, suggest that Titan seas, lakes or oceans are made up of methane. Nevertheless, Titan harbors a complex organic chemistry which involves other hydrocarbon molecules such as ethane, acetylene, hydrogen cyanid, etylene and more complex hydrocarbon constituents. Hence, the possibility of an ethane sea has been advanced and it can't be ruled out at today's point of knowledge.

The image above represents "Ontario Lacus", a giant lake spotted in Titan's south pole by the VIMS ( Visual and Infrared Mapping Spectrometer ) onboard the Cassini spacecraft. This lake or sea is around 230 km long. As the south pole is currently tilted towards the Sun ( Summer period ), the region absorbs a relatively high amount of energy compared to the winter hemisphere ( northern hemisphere ). As a result, the evaporation process of organic compounds ( methane, ethane or acetylene) is higher. And this phenomenon explains well the presence of the cloud formations identified in the south pole by the infrared camera of the Cassini probe. It is very likely that Ontario Lacus is a primary source for those rapidly dissipating formations of clouds.

Lightning on Titan

This rendering shows flashes of lightning on Titan lowering the opacity of the atmosphere so that the disk of Saturn can be briefly seen through the red haze from the surface of Titan.For a Titanian observer, Saturn appears 11 times larger than the Moon of the Earth as seen from the surface of our planet and Saturn is also much more reflective than our moon with an albedo close to 50% compared to an albedo of 12% for the Satellite of the Earth.

Image Source: Marc Lafferre, year 2005

If you have any comment to bring or any artistic image of Titan to submit to us, please send us the e mail at the following web address: titanteammlgc@yahoo.com or fill in the form below ( for the form, the size of the file should not be over 200 ko ).

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