Oberon is the outermost major moon of the planet Uranus. It is the
second largest and second most massive of Uranian moons, and the ninth
most massive moon in the Solar System. Discovered by William Herschel
in 1787, Oberon is named after a character in Shakespeare's A Midsummer
Night's Dream. Its orbit lies partially outside Uranus's magnetosphere.
Oberon consists of approximately equal amounts of ice and rock, and is
likely differentiated into a rocky core and an icy mantle. A layer of
liquid water may be present at the core/mantle boundary. The surface of
Oberon, which is dark and slightly red in color, appears to have been
primarily shaped by asteroid and comet impacts. It is covered by
numerous impact craters reaching 210 km in diameter. Oberon possesses a
system of canyons (scarps) formed as a result of the expansion of its
interior during its early evolution. This moon probably formed from the
accretion disk that surrounded Uranus just after the planet's
formation. As of 2010, the Uranian system has been studied up close
only once: by the spacecraft Voyager 2 in January 1986. It took several
images of Oberon, which allowed mapping of about 40% of the moon’s
surface.
Read the rest of this article:
<http://en.wikipedia.org/wiki/Oberon_%28moon%29>
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Today's selected anniversaries:
1422:
As the only heir to the throne, Henry VI became King of England at the
age of eight months following the death of his father Henry V.
<http://en.wikipedia.org/wiki/Henry_VI_of_England>
1888:
Mary Ann Nichols' body was found on the ground in front of a gated
stable entrance in Buck's Row, London, allegedly the first victim of
the unidentified serial killer known as Jack the Ripper .
<http://en.wikipedia.org/wiki/Jack_the_Ripper>
1907:
The Great Game: Russia and the United Kingdom signed the Anglo-Russian
Entente, defining their respective spheres of interest in Persia,
Afghanistan, and Tibet.
<http://en.wikipedia.org/wiki/Anglo-Russian_Entente>
1958:
A parcel bomb sent by Ngo Dinh Nhu, younger brother and chief adviser
of South Vietnamese President Ngo Dinh Diem, failed to kill Sihanouk of
Cambodia.
<http://en.wikipedia.org/wiki/Ngo_Dinh_Nhu>
1986:
After a collision with a freighter, the Soviet ocean liner Admiral
Nakhimov sank in the Tsemes Bay area of the Black Sea within seven
minutes, killing more than 400 people on board.
<http://en.wikipedia.org/wiki/SS_Admiral_Nakhimov>
1997:
Princess Diana, her companion Dodi Fayed, and their driver Henri Paul
were killed in a high speed car accident in the Pont de l'Alma road
tunnel in Paris.
<http://en.wikipedia.org/wiki/Death_of_Diana%2C_Princess_of_Wales>
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Wiktionary's word of the day:
rhabdomyolysis (n):
(medicine) The rapid disintegration of striated muscle tissue
accompanied by the excretion of myoglobin in the urine
<http://en.wiktionary.org/wiki/rhabdomyolysis>
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Wikiquote quote of the day:
There's not a war between Muslims and non-Muslims, but between
extremists and moderates of all the religions. ... What is important is
not to live in fear. The most dangerous thing to do is to give up and
lose hope. The main enemy is not terrorism or extremism, but ignorance.
--Queen Rania of Jordan
<http://en.wikiquote.org/wiki/Queen_Rania_of_Jordan>