Pluto is no longer a planet

Nearly 2,500 scientists are meeting in Prague, the Czech Republic agreed to vote Pluto from the list of planets in the solar system.

(Photo: universetoday.com)

This small, remote object is downgraded to a lower rank.

The decision of the International Astronomical Society (IAU) means that textbooks will now have to rewrite the solar system with only eight large planets.

The decision comes after scientists agree on the criteria to classify a celestial body as a planet:

- It has to fly in orbit around the sun.
- It must be large enough to have a nearly circular shape
- Its trajectory must be separate from other objects

Under these criteria, Pluto has dropped himself from the rankings because its flat elliptical orbit cuts through Neptune's orbit .

Pluto, described in 1930 by American astronomer Clyde Tombaugh, will now be considered a " dwarf planet ".

Its rank is the new object found in 2003 UB313 - the largest asteroid in the Ceres - and Charon solar system - its largest moon.

Pluto's position dispute has lasted for many years, because of its small size and its remote location compared to the other " traditional " planets of the solar system. It is even smaller than some satellites of other planets in the solar system. Its trajectory is also more inclined than all other planets. And yet, most recently, it has been found that objects that are larger or approximately equal to them in the outer region of the solar system are the Kuiper belt.

The solar system follows new criteria, consisting of only 8 large traditional planets.Pluto is classified as "dwarf planet" along with Ceres, Charon and 2003 UB313.(Photo: BBC)

T. An