Definition of Pluto Assignment PDF

Running head: DEFINITION OF PLUTO 1
Definition of Pluto
Student’s Name
Institutional Affiliation

DEFINITION OF PLUTO 2
Definition of a planet
An object is referred to as a planet if it possesses the following characteristics:
 Revolves round the sun
 Has substantial mass to be spherical or nearly round
 It has removed small objects or debris from the periphery of its orbit
 It is not a satellite or a moon of another body
These definitions were put forward by the International Astronomical Union, IAU. The name
planet comes from the Greek word ‘wanderer’. Planet exploration dates back to the year 1600
with the invention of the telescope. This helped astronomers like Galileo Galilei to observe the
orbiting moons of Jupiter. Little was known about Uranus, Neptune calling for advanced
exploration of an unknown planet X that was believed to be disturbing the orbit of these two
planets. It was during this scouring that Clyde Tombaugh discovered Pluto in 1930 which was
beyond Neptune’s orbit (Howell, 2018).
Why Pluto Was a Planet
Planet was previously a planet since it orbits round the sun. Similarly, it has an eccentric
orbit which is about 30 to 49 billion km from the sun. Moreover, the satellite images took by new
horizons spacecraft outlines a spherical body of ice and rocks. Funny enough, sun rays take 5
hours to reach the surface of Pluto.
Why Pluto Was demoted as a Planet
The IAU developed a new definition of bodies that met planetary criteria but have not yet
cleared debris from the periphery of its orbit. They referred to these bodies as ‘dwarf’ planets.