This Day in History: Pluto Is Discovered
  • 3 years ago
This Day in History: , Pluto Is Discovered.
February 18, 1930.
Once believed to be the ninth planet,
Pluto was discovered at the Lowell Observatory
in Flagstaff, AZ, by astronomer Clyde W. Tombaugh.
Tombaugh discovered the
tiny dwarf planet using a new astronomic technique
of photographic plates combined with a blink microscope.
Pluto was given the Roman name for the
god of the underworld in Greek mythology
due to its surface temperature of -360° F.
Nearly four billion miles away from the sun,
it takes Pluto approximately
248 years to complete one orbit. .
Pluto's only known moon, Charon,
has a diameter of a mere 737 miles.
In 2006, it was announced that Pluto would
no longer be considered a planet because its
orbit crosses into the orbit of planet Neptune.
While widely referred to as a dwarf planet, many argue that it should still be considered a planet.
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