Question

Why have Pluto and the objects like it been deleted from the list of planets? What is the new name given to these objects? State their name in the order of increasing from the distance.

Answer 1

1. Planets- The word planet comes from the Greek word which means “wanderer”.
2. According to the International Astronomical Union (IAU), a celestial object is called a planet if-
   (I) It has a fixed clear orbit around the sun.
   (II) It is massive enough for the gravity to make it round.
   (III) It should not take more than two centuries to revolve around the sun.
3. Pluto is not big enough to have a clear orbit and due to its highly elliptical orbit, it crosses Neptune's orbit.
4. Moreover, Pluto takes 248 years to complete one revolution around the sun.
5. Therefore in 2006 IAU demoted Pluto as a planet because it no longer fit in the modern definition of the planet.

Plutons:

1. It is the new name that was given to Pluto and objects beyond Pluto.

Name of plutons in the order of increasing from the distance:

1. Pluto, Charon, and Xena.