92 years since the discovery of Pluto

This February 18 marks the 92nd anniversary of the discovery of Pluto by the American astronomer Clyde William Tombaugh, from the Lowell Observatory in Flagstaff, Arizona.

It was considered the ninth and smallest planet in the solar system by the International Astronomical Union and by public opinion from its location in 1930 until 2006, -when it was reclassified as a dwarf planet-, although its definition has always been the subject of controversy among scientists. astronomers.

For many years there was a belief that Pluto it was a satellite of Neptune that had ceased to be a satellite by reaching a second cosmic speed. However, this theory was rejected in the 1970s.

After an intense debate, and with the proposal of the Uruguayan astronomers Julio Ángel Fernández and Gonzalo Tancredi before the General Assembly of the International Astronomical Union in Prague, Czech Republic, it was unanimously decided in 2006 to reclassify Pluto as a dwarf planet, requiring that a planet must have orbital dominance.

Its classification as a planet was proposed in the draft resolution, but it disappeared from the final resolution, approved by the IAU General Assembly. Since September 7, 2006, it has the number 134340, granted by the Center for Minor Planets.

But since then, many scientists who believe that Pluto It must be a planet again. But not because it has a climate, a layered atmosphere, possible organic compounds, liquid oceans and its own moons, as experts reason based on scientific evidence, but because it has been learned that way in schools, an argument that is also valid for society. for the Preservation of Pluto as a Planet.

Pluto It has an eccentric and highly inclined orbit with respect to the ecliptic, which it travels approaching at its perihelion to the interior of Neptune’s orbit. It also has five satellites: Charon, Nix, Hydra, Cerberus and Styx, which are celestial bodies that share the same category, reports Wikipedia.

Its great distance from the Sun and the Earth, together with its small size, prevent it from shining above magnitude 13.8 at its best (orbital perihelion and opposition), which is why it can only be seen with telescopes from 200 mm aperture, photographically or with a CCD camera.

Even at its best, it appears as a stellar-looking, yellowish, featureless, punctual star (apparent diameter less than 0.1 arc seconds). It was not until 2015 that the New Horizons space probe passed over the planet and allowed its real appearance to be clearly seen for the first time.