<P> Pluto was discovered by Clyde Tombaugh in 1930 and was originally considered to be the ninth planet from the Sun . After 1992 , its status as a planet was questioned following the discovery of several objects of similar size in the Kuiper belt . In 2005 , Eris , a dwarf planet in the scattered disc which is 27 % more massive than Pluto , was discovered . This led the International Astronomical Union ( IAU ) to define the term `` planet '' formally in 2006 , during their 26th General Assembly . That definition excluded Pluto and reclassified it as a dwarf planet . </P>
<P> Pluto was discovered by Clyde Tombaugh in 1930 and was originally considered to be the ninth planet from the Sun . After 1992 , its status as a planet was questioned following the discovery of several objects of similar size in the Kuiper belt . In 2005 , Eris , a dwarf planet in the scattered disc which is 27 % more massive than Pluto , was discovered . This led the International Astronomical Union ( IAU ) to define the term `` planet '' formally in 2006 , during their 26th General Assembly . That definition excluded Pluto and reclassified it as a dwarf planet . </P>
what year did pluto become a dwarf planet
what year did pluto become a dwarf planet
2006
2006