Pluto — An enduringly interesting celestial object

Pluto is a celestial object that had caught the imagination of increasingly ‘sky-aware’ people all around the world, perhaps due to the inspiring story of its discovery by a young amateur astronomer. It was celebrated as the ninth planet of the solar system for decades. A question mark hung over its nomenclature as a planet from the time of the discovery of its moon Charon, when a good estimate of its very small mass in comparison with other planets was obtained. The discovery of UB 313, a body in the outer regions of the solar system that was more massive than Pluto, magnified this question mark and compelled the International Astronomical Union to review the definition of the word ‘Planet’. A new and physical definition was given to this word and Pluto was categorized as a dwarf planet. The beauty of this physical definition of a planet is something that would definitely have been appreciated by Clyde Tombaugh — who once made this beautifully simple statement about Pluto, while its status was being questioned — “It is there, whatever it is”. Yes, whatever it is, Pluto is one celestial object that is somehow very endearing to everyone around the world and is also an object whose studies are compelling certain paradigm shifts in our understanding of the structure and evolution of the solar system.