Uranus is the seventh planet from the Sun and the third largest and
fourth most massive planet in the solar system. Uranus was the first
planet discovered in modern times. Though it is visible to the naked
eye like the five classical planets, it was never recognised as a
planet by ancient observers due to its dimness. Sir William Herschel
announced its discovery on March 13, 1781, expanding the known
boundaries of the solar system. Uranus' atmosphere, while still
composed primarily of hydrogen and helium, contains a higher
proportion of "ices" such as water, ammonia and methane, along with
the usual traces of hydrocarbons. It is the coldest planetary
atmosphere in the Solar System, with a minimum temperature of 49 K,
and has a complex layered cloud structure, in which water is thought
to make up the lowest clouds, while methane makes up the uppermost
layer of clouds. Like the other giant planets, Uranus has a ring
system, a magnetosphere, and numerous moons. The Uranian system has a
unique configuration among the planets because its axis of rotation is
tilted sideways, nearly into the plane of its revolution about the
Sun; its north and south poles lie where most other planets have their
equators. In 1986, images from Voyager 2 showed Uranus as a virtually
featureless planet in visible light without the cloud bands or storms
associated with the other giants. The wind speeds on Uranus can reach
250 m/s.
Read the rest of this article:
http://en.wikipedia.org/wiki/Uranus
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Today's selected anniversaries:
1724:
Tumult of Thorn (Toruń): Polish authorities executed the Mayor of
Toruń, Royal Prussia and nine other Lutheran citizens following
tensions between Protestants and Catholics.
(
http://en.wikipedia.org/wiki/Tumult_of_Thorn_%28Toru%C5%84%29)
1732:
The Royal Opera House opened at Covent Garden in London.
(
http://en.wikipedia.org/wiki/Royal_Opera_House)
1815:
Michel Ney, Marshal of France, was executed by a firing squad near
Paris' Jardin du Luxembourg for supporting Napoleon Bonaparte.
(
http://en.wikipedia.org/wiki/Michel_Ney)
1941:
World War II: The Imperial Japanese Navy made its attack on Pearl
Harbor, Oahu, Hawaii.
(
http://en.wikipedia.org/wiki/attack_on_Pearl_Harbor)
1949:
Chinese Civil War: The government of the Republic of China relocated
from Mainland China to Taipei on the island of Taiwan.
(
http://en.wikipedia.org/wiki/Taipei)
1988:
An earthquake with a moment magnitude of 7.2 struck the Spitak
region of Armenia, then part of the Soviet Union, killing at least
50,000 people.
(
http://en.wikipedia.org/wiki/1988_Spitak_earthquake)
1995:
The Galileo spacecraft arrived at Jupiter, a little more than six
years after it was launched by Space Shuttle Atlantis during Mission
STS-34.
(
http://en.wikipedia.org/wiki/Galileo_spacecraft)
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Wiktionary's Word of the day:
matter-of-factly: As though stating a fact.
(
http://en.wiktionary.org/wiki/matter-of-factly)
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Wikiquote of the day:
It's an alethiometer. It's one of only six that were ever made. Lyra,
I urge you again: keep it private. ... It tells you the truth. As for
how to read it, you'll have to learn by yourself. Now go — it's
getting lighter... -- The Golden Compass
(
http://en.wikiquote.org/wiki/Philip_Pullman)