Why Pluto is no longer a real planet?

Photo Credit: Nasa

Pluto moves around the sun in an elongated ellipse in about 248 years .  

Orbit 

Photo Credit: Nasa

Photo Credit: Nasa

Between about 4.4 and 7.4 billion kilometers . For comparison: At about 150 million kilometers, the Earth is only a stone's throw from the sun. 

Distance from the sun 

2,374 kilometers - only a fifth of the diameter of the Earth (12,756) and less than half of the largest moons of Jupiter and Saturn. 

Diameter 

Photo Credit: Nasa

Because of its great distance from the sun, the temperature on its surface drops to minus 249 degrees Celsius . 

Temperature 

Photo Credit: Nasa

Unlike the "mainstream" planets from Mercury, Mars to Neptune, Pluto orbits the sun in long, stretched-out circles . 

Photo Credit: Nasa

It does so at a highly unusual angle. Pluto is round, as a planet should be, but much smaller. 

Photo Credit: Nasa

In 2006, the International Astronomical Union decided that Pluto is not a full-fledged planet, but only a dwarf planet . Some scientists criticize this as petty. 

Photo Credit: Nasa

The parliament of the US state of Illinois decided in 2009 that Pluto is a planet after all.  

Photo Credit: Nasa