Question

Why is Pluto taken out from the list of planets?

Answer 1

Answer:

The International Astronomical Union (IAU) downgraded the status of Pluto to that of a dwarf planet because it did not meet the three criteria the IAU uses to define a full-sized planet. Essentially Pluto meets all the criteria except one—it “has not cleared its neighboring region of other objects.”

Answer 2

• The International Astronomical Union (IAU) downgraded the status of Pluto to that of a dwarf planet because it did not meet the the three criteria the IAU uses to define a full-sided planet.
• Essentially Pluto meets all the criteria except one- it has not cleared its neighboring region of other objects.
• In August 2006 the The International Astronomical Union (IAU) downgraded the status of Pluto to that of a " dwarf planet".
• A "dwarf planet", as defined by the IAU , is a celestial body in the direct orbit of the Sun that is massive enough that its shape is controlled by gravitational forces rather than mechanical forces, but has no cleared its neighboring region of other objects.
• So the three criteria of the IAU for a full-sized planets are:

                         It is in orbit around the Sun.

                         It has sufficient mass to assume hydrostatic equilibrium.

                         It has "cleared the neighborhood" around its orbit.

• Sounds like a minesweeper in space. This means that the planet has become gravitational dominant-there are no other bodies of comparable size other than its own satellites or those otherwise under its gravitational influence.