Question : EXCLUSION OF PLUTO FROM SOLAR SYSTEM



(a) whether the astronomers of the World have excluded Planet `Pluto` from the Solar System;

(b) if so, the reasons therefor;

(c) whether Indian astronomers have agreed to the said view; and

(d) if so, the details therof?

Answer given by the minister


MINISTER OF STATE IN THE PRIME MINISTER`S OFFICE (SHRI PRITHVIRAJ CHAVAN):

(a) Pluto is now reclassified as a dwarf planet.

(b),(c)&(d) As new objects are being discovered going around other stars, astronomers felt that there should be uniform criteria for deciding to name such objects as planets or into any other category. Examples of such criteria are that the planet should have enough force of gravity to get into spherical shape and the barycentre of the planet and its satellite, if any, should be inside the planet. Since, Pluto does not satisfy such criteria, it is not called a planet any more and is labelled a dwarf planet.

The above re-classification was done by the International Astronomical Union (IAU) at its General Assembly meeting held in Prague on 24 August 2006. The Indian contingent was also present in this General Assembly meeting.