Triton is the largest moon of the planet Neptune, discovered on
October 10, 1846, by William Lassell. It is the only large moon in the
Solar System with a retrograde orbit, which is an orbit in the opposite
direction to its planet's rotation. At 2700 km in diameter, it is the
seventh-largest moon in the Solar System. Because of its retrograde
orbit and composition similar to Pluto's, Triton is thought to have
been captured from the Kuiper belt. Triton consists of a crust of
frozen nitrogen over an icy mantle believed to cover a substantial core
of rock and metal. The core makes up two-thirds of its total mass.
Triton has a mean density of 2.061 g/cm3 and is composed of
approximately 15–35% water ice. Triton is one of the few moons in the
Solar System known to be geologically active. As a consequence, its
surface is relatively young, with a complex geological history revealed
in intricate and mysterious cryovolcanic and tectonic terrains. Part of
its crust is dotted with geysers believed to erupt nitrogen. (more...)
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Today's selected anniversaries:
The Council of Chalcedon, the fourth ecumenical council in
Christianity, opened. It repudiated the Eutychian doctrine of
monophysitism, and set forth the Chalcedonian Creed.
Demetrius Zvonimir, the last native king who exerted any real power
over the entire Croatian state, was crowned.
Composer Gustav Mahler was appointed the director of the Vienna Court
Marxist revolutionary and guerrilla leader Che Guevara was captured
near La Higuera, Bolivia.
At Linate Airport in Milan, Italy, Scandinavian Airlines Flight SK686
collided on take-off with a Cessna Citation II business jet, killing
Wiktionary's word of the day:
(historical) A Christian ascetic who lived alone on top of a tall
Wikiquote quote of the day:
One always feels that a merely educated man holds his philosophical
views as if they were so many pennies in his pocket. They are separate
from his life. Whereas with a cultured man there is no gap or lacuna
between his opinions and his life. Both are dominated by the same
organic, inevitable fatality. They are what he is.
--John Cowper Powys
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