Dwarf planet – Pluto

Pluto  

The Pluto is one of the dwarf planet, which was the first discovered Kuiper belt object. The scientist Clyde Tombaugh found this Planet, which is the ring of bodies after the orbit of Neptune.      

Structure of Pluto

                 This is the ninth largest planet, which is the largest trans-Neptunian object in terms of volume, but less larger than the other dwarf planet Eris. The Planet has an inclined and a slightly eccentric orbit for the rotation, which has the value of 30-49 astronomical units from the sun. This Planet is also the tenth largest object, which directly rotates around the sun. The discoverer of the Pluto, Clyde Tombaugh in 1930, declared that this Planet was the ninth planet from the Sun.

Features

            The Planet contains the ice and rock, like the Kuiper belt objects. This Planet is comparatively small, which is one third of the volume of the Moon and one sixth by its mass.  This Planet comes nearer to the Sun periodically than the Neptune,  but it does not collide due to the stable orbital resonance with the Planet Neptune. It takes 5.5hours for the sunlight, to come to Pluto with an average distance of 39.5AU.

Inner structure

            The inner structure contains the crust of water ice, liquid water ocean and the silicate core. The density of the Pluto, is more or less  of 1.86g/cm3. In this Planet, the radioactive elements, heats the ice, which leads to the settlement of the rocks inside the dense core and the mantle of water ice. Then the diameter of the core of Pluto is 1700Km(the value got out of estimation from New Horizons).   

Atmosphere

            The tenuous atmosphere of the Pluto, contains the Methane, Nitrogen and carbon monoxide,  which stay in equilibrium with the surface ice in the Pluto.

Moons of the Pluto

            This Planet has five moons, which are known. They are Charon, Styx, Kerberos, Hydras and the Nix. Here the Charon is the largest moon of Pluto, with a  diameter of about half of the Pluto. In some instance, the Pluto and the Charon are seen as the binary system, since the orbit’s barycenter of these Planets do not be inside the body.

Controversy on Planet Status of Pluto

            After the discovery of many objects having the size as same as the Kuiper belt, the planet status of the Planet was questioned in 1992. A dwarf Planet, known as Eris, which was 27% larger than the Pluto was newly found in 2005.  This forced the International Astronomical Union(IAU) to explain the term Planet, in the 26th General Assembly in 2006. This definition eliminated the Pluto and added it to the dwarf Planet list.

IAU Planet’s Definition

            In August 2006, the IAU resolution, recreated the definition for the word Planet. As per this resolution, any object in the Solar system, must satisfy these three conditions to become a Planet.

1) The object in the Solar system, should be in an orbit, rotating the Sun.

2) The object should be sufficiently large, so that its own gravity rounds that object.  Its gravity must form into a shape, as per the hydrostatic equilibrium definition. 

3)  That object should clear the neighborhood, throughout its  rotating path.

The Pluto fails to satisfy the last condition, so it lost the Planet status.         

Orbit

            The orbital period of this planet, is about 248 years.  As compared with the other Planets, we can see the orbital characteristics of Pluto are different from others. The orbits of the other planets, have nearly a circular path or an  elliptical path around the Sun. This Planet has a slightly inclined and eccentric orbit.           

Perihelion and Aphelion

            The Planet has the Perihelion of 29.658AU or 4.43682billion Km, which is the nearest approach to the Sun.

This Planet holds the Aphelion of about 49.305AU or 7.37593billion Km, which is the farthest distance from the sun.

Research On Pluto            

On 14th July 2015, the spacecraft New Horizons orbited the Planet for the first time. By orbiting the Planet, the New Horizons captured the observations and the details about the Pluto and its moon.  The astronomers in September 2016, declared that the brown cap of the north pole of the Charon contains the organic macro molecules and tholins, which is the source of the start of life. It is believed that these elements are present in the Pluto’s moon, due to the release of the nitrogen, methane and other gases from the Pluto atmosphere had transferred to their orbiting moons.