Planet Nine is a hypothetical planet in the outer region of the Solar
System. Its gravitational effects could explain the unlikely clustering
of orbits for a group of extreme trans-Neptunian objects, bodies with
average distances from the Sun that are more than 250 times that of
Earth. These objects tend to make their closest approaches to the Sun in
one sector, and their orbits are similarly tilted. Their improbable
alignments suggest that an undiscovered planet may be shepherding the
orbits of the most distant known Solar System objects. Planet Nine would
have a predicted mass five to ten times that of Earth, and an elongated
orbit extending 400 to 800 times as far from the Sun as the Earth's. It
may have been ejected from its original orbit by Jupiter during the
genesis of the Solar System, wrested from another star, captured as a
rogue planet, or pulled into an eccentric orbit by a passing star.
Read more: <https://en.wikipedia.org/wiki/Planet_Nine>
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Today's selected anniversaries:
1917:
First World War: The Canadian Corps began the first wave of
attacks at the Battle of Vimy Ridge in Vimy, France.
<https://en.wikipedia.org/wiki/Battle_of_Vimy_Ridge>
1942:
World War II: Japanese forces defeated Allied troops at the
Battle of Bataan on the Bataan Peninsula in the Philippines before
beginning to forcibly transfer more than 90,000 prisoners of war to
prison camps in the Bataan Death March.
<https://en.wikipedia.org/wiki/Bataan_Death_March>
1959:
NASA announced the selection of the Mercury Seven, the first
astronauts in Project Mercury.
<https://en.wikipedia.org/wiki/Mercury_Seven>
1999:
President of Niger Ibrahim Baré Maïnassara was shot to death
by soldiers in Niamey.
<https://en.wikipedia.org/wiki/Ibrahim_Bar%C3%A9_Ma%C3%AFnassara>
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Wiktionary's word of the day:
grandfather:
1. (transitive, chiefly US, law) To retain existing laws or rules for (a
person or organization previously affected by them).
2. (intransitive, chiefly US, law) To retain existing laws or rules only
for people or organizations previously affected by them, and to apply
new laws or rules to the unaffected people or organizations.
<https://en.wiktionary.org/wiki/grandfather>
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Wikiquote quote of the day:
No one is more dangerous than someone who thinks he has "The
Truth". To be an atheist is almost as arrogant as to be a
fundamentalist.
--Tom Lehrer
<https://en.wikiquote.org/wiki/Tom_Lehrer>