Explanation:
Is Pluto the largest dwarf planet? No!
Currently, the largest known dwarf planet is
(136199) Eris,
renamed last week from 2003 UB313.
Eris is just slightly larger than Pluto, but orbits as far as twice
Pluto's distance from the Sun.
Eris is shown above in an image taken by a 10-meter
Keck Telescope from
Hawaii,
USA.
Like Pluto, Eris has a moon, which has been
officially named by the
International Astronomical Union
as (136199) Eris I (Dysnomia).
Dysnomia is visible above just to the right of Eris.
Dwarf planets
Pluto and Eris are
trans-Neptunian objects that orbit in the
Kuiper belt
of objects past Neptune.
Eris was discovered in 2003, and is likely composed of
frozen water-ice and
methane.
Since Pluto's recent demotion by the
IAU from planet to dwarf planet status,
Pluto
has recently also been given a new numeric designation: (134340) Pluto.
Currently, the only other officially designated "dwarf planet" is (1)
Ceres.
