The term planet came from the Greek word “planetes” meaning ‘wandering star’. Although there used to be nine planets including Pluto, the naked eye can only view five planets, Mercury, Venus, Mars, Jupiter and Saturn. When the design of the refracting telescope was initially invented in 1608 by Hans Lippershey, a German-Dutch lensmaker, the chance to discover Uranus and Neptune came about. Although it was commonly believed, that Galileo Galilei, an Italian astronomer, was the inventor of the telescope.
In 1930, Pluto was considered as planet when an astronomer from Lowell Laboratoey, Clyde Tombaugh saw a tiny dot that was moving to and fro against the view of scattered stars in the sky. However, in 2005 astronomers spotted another heavenly body called Eris where it was initially thought to be larger than pluto. Since this was so, Eris could all the more be as planet because it is larger than pluto.
Experts from different universities debated on various planet definitions. If the description of a planet is any round object in the outer space but is smaller than a star, then it would make pluto a planet again as well as other moons in the solar system. It was further classified that Pluto must have been mistaken or misunderstood as a planet during its discovery and was never a planet in the first place.
Researchers from International Astronomical Union (IAU) voted in order to reclasify Pluto from being a planet to a dwarf planet in August 24, 2006. Such change will require to rewrite books.
