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Xanadu (Titan)
Encyclopedia
Xanadu is a highly reflective area on the leading hemisphere of Saturn's moon Titan
. Its name comes from Xanadu
, the legendary palace described in Samuel Taylor Coleridge
's poem Kubla Khan
.
The feature was first identified in 1994 by astronomers using the Hubble Space Telescope
at infrared
wavelengths, and has recently been imaged in more detail by the Cassini space probe. Xanadu is about the size of Australia
. Preliminary observations indicate that Xanadu is a plateau-like region of highly reflective water ice, contrasting somewhat with the darker lower regions. These in turn seem to contrast quite sharply with the very dark maria
, which were once believed to be seas of liquid hydrocarbons, but are now thought to be plain
s.
Recent images by Cassini during encounters in October and December 2004 reveal complex albedo patterns
in the western portion of Xanadu. While scientists are still debating the significance and cause of the albedo patterns, one likely culprit is tectonism. Evidence for this exists in a pattern of criss-crossing dark lineaments near the western side of Xanadu. Scientists are also investigating the boundary between Xanadu and Shangri-la
, a dark region to the west. The shape of the boundary suggests that the dark material embays the bright terrain.
Radar images taken by Cassini have revealed dunes, hills, rivers and valleys present on Xanadu. The features are likely carved in ice, rather than solid ground, by liquid methane
or ethane
.
Titan (moon)
Titan , or Saturn VI, is the largest moon of Saturn, the only natural satellite known to have a dense atmosphere, and the only object other than Earth for which clear evidence of stable bodies of surface liquid has been found....
. Its name comes from Xanadu
Xanadu
-Description of Xanadu by Toghon Temur :The lament of Toghon Temur Khan , concerning the loss of Daidu and Heibun Shanduu in 1368, is recorded in many Mongolian historical chronicles...
, the legendary palace described in Samuel Taylor Coleridge
Samuel Taylor Coleridge
Samuel Taylor Coleridge was an English poet, Romantic, literary critic and philosopher who, with his friend William Wordsworth, was a founder of the Romantic Movement in England and a member of the Lake Poets. He is probably best known for his poems The Rime of the Ancient Mariner and Kubla...
's poem Kubla Khan
Kubla Khan
Kubla Khan is a poem by Samuel Taylor Coleridge, completed in 1797 and published in Christabel, Kubla Khan, and the Pains of Sleep in 1816...
.
The feature was first identified in 1994 by astronomers using the Hubble Space Telescope
Hubble Space Telescope
The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...
at infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
wavelengths, and has recently been imaged in more detail by the Cassini space probe. Xanadu is about the size of Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. Preliminary observations indicate that Xanadu is a plateau-like region of highly reflective water ice, contrasting somewhat with the darker lower regions. These in turn seem to contrast quite sharply with the very dark maria
Lunar mare
The lunar maria are large, dark, basaltic plains on Earth's Moon, formed by ancient volcanic eruptions. They were dubbed maria, Latin for "seas", by early astronomers who mistook them for actual seas. They are less reflective than the "highlands" as a result of their iron-rich compositions, and...
, which were once believed to be seas of liquid hydrocarbons, but are now thought to be plain
Plain
In geography, a plain is land with relatively low relief, that is flat or gently rolling. Prairies and steppes are types of plains, and the archetype for a plain is often thought of as a grassland, but plains in their natural state may also be covered in shrublands, woodland and forest, or...
s.
Recent images by Cassini during encounters in October and December 2004 reveal complex albedo patterns
Albedo feature
An albedo feature is a large area on the surface of a planet which shows a contrast in brightness or darkness with adjacent areas....
in the western portion of Xanadu. While scientists are still debating the significance and cause of the albedo patterns, one likely culprit is tectonism. Evidence for this exists in a pattern of criss-crossing dark lineaments near the western side of Xanadu. Scientists are also investigating the boundary between Xanadu and Shangri-la
Shangri-la (Titan)
Shangri-la is a large, dark region of Saturn's moon Titan at . It is named after Shangri-La, the mythical paradise in Tibet. It is thought to be an immense plain of dark material. It is thought that these regions of Titan were seas, but that they are now dry....
, a dark region to the west. The shape of the boundary suggests that the dark material embays the bright terrain.
Radar images taken by Cassini have revealed dunes, hills, rivers and valleys present on Xanadu. The features are likely carved in ice, rather than solid ground, by liquid methane
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
or ethane
Ethane
Ethane is a chemical compound with chemical formula C2H6. It is the only two-carbon alkane that is an aliphatic hydrocarbon. At standard temperature and pressure, ethane is a colorless, odorless gas....
.
External links
- Patch of Saturn's Moon Resembles Earth
- Cassini finds land on Titan Lucy Sherriff (The RegisterThe RegisterThe Register is a British technology news and opinion website. It was founded by John Lettice, Mike Magee and Ross Alderson in 1994 as a newsletter called "Chip Connection", initially as an email service...
) Thursday 20 July 2006 13:36 GMT