Titania (moon)

Titania (pronounced /tɨˈtɑnjə/ ti-taan'-yə, also /taɪˈteɪniə/ tye-tay'-nee-ə) is the largest moon of Uranus and the eighth largest moon in the Solar System.

1 Discovery
2 Name and pronunciation
3 Physical characteristics
4 Occultation
5 See also
6 Notes
7 External links

Discovery

Titania was discovered on January 11, 1787 by William Herschel. He reported it and Oberon the same year.^[1] He later reported four more satellites, which turned out to be spurious.^[2]

Name and pronunciation

Image:PIA00039 Titania.jpg

This Voyager 2 image of Titania shows enormous rifts.

The names of Titania and the other four satellites of Uranus then known were suggested by Herschel's son John Herschel in 1852 at the request of William Lassell, who had discovered Ariel and Umbriel the year before.^[3] Lassell had earlier endorsed Herschel's 1847 naming scheme for the seven then-known satellites of Saturn and had named his newly-discovered eighth satellite Hyperion in accordance with Herschel's naming scheme in 1848.

All of the moons of Uranus are named for characters from Shakespeare or Alexander Pope. Titania was named after Titania, the Queen of the Faeries in A Midsummer Night's Dream.

Shakespeare's character's name is pronounced /tɨˈtɑnjə/, but the moon is often pronounced /taɪˈteɪniə/, by analogy with the familiar chemical element titanium.

It is also designated Uranus III.

Physical characteristics

Image:Messin Chasma.jpg

The rift Messin Chasma is highlighted in this view of Titania's crescent phase (apparently a reprojection of the image above).

So far the only close-up images of Titania are from the Voyager 2 probe, which photographed the moon during its Uranus flyby in January, 1986. At the time of the flyby the southern hemisphere of the moon was pointed towards the Sun so only it was studied.

Although its interior composition is uncertain, one model suggests that Titania is composed of roughly 50% water ice, 30% silicate rock, and 20% methane-related organic compounds. A major surface feature is a huge canyon that dwarfs the scale of the Grand Canyon on Earth and is in the same class as the Valles Marineris on Mars or Ithaca Chasma on Saturn's moon Tethys.

Scientists recognise the following geological features on Titania:

Occultation

On September 8, 2001, Titania occulted a faint star; this was an opportunity to both refine its diameter and ephemeris, and to detect any extant atmosphere. The data revealed no atmosphere to a surface pressure of 0.03 microbars; if it exists, it would have to be far thinner than that of Triton or Pluto.^[4]^[5]

Notes

^ Herschel, "An Account of the Discovery of Two Satellites Revolving Round the Georgian Planet", Philosophical Transactions of the Royal Society of London, Vol. 77, pp. 125-129, 1787; and "On George's Planet and its satellites", Philosophical Transactions of the Royal Society of London, Vol. 78, pp. 364-378, 1788.
^ "On the Discovery of Four Additional Satellites of the Georgium Sidus; The Retrograde Motion of Its Old Satellites Announced; And the Cause of Their Disappearance at Certain Distances from the Planet Explained", Philosophical Transactions of the Royal Society of London, Vol. 88, pp. 47-79, 1798.
^ http://adsabs.harvard.edu//full/seri/AN.../0034//0000169.000.html Adsabs.harvard.edu Retrieved on 05-19-07
^ http://www.obspm.fr/actual/nouvelle/mar02/titania.en.shtml Obspm.fr Retrieved on 05-19-07
^ http://www.lesia.obspm.fr/~titania/results.html Lesia.obspm.fr Retrieved on 05-19-07

External links

Titania Profile by NASA's Solar System Exploration

v • d • e Uranus
Major Moons	Ariel · Miranda · Oberon · Titania · Umbriel
Characteristics	Atmosphere · Rings of Uranus · Moons
Discovery	William Herschel · William Lassell
Exploration	Voyager program · Voyager 2
Other	15 Orionis · Uranus-crosser asteroid · In fiction

v • d • e Natural satellites of the Solar System
Planetary satellites	Terrestrial · Martian · Jovian · Saturnian · Uranian · Neptunian
Other satellite systems	Plutonian · Eridian · Asteroid satellites
Largest satellites	Ganymede · Titan · Callisto · Io · Moon · Europa · Triton Titania · Rhea · Oberon · Iapetus · Charon · Umbriel · Ariel · Dione · Tethys · Enceladus · Miranda · Proteus · Mimas
Inner satellites · Trojans · Irregulars · List · List by diameter · Timeline of discovery · Naming