Discuss why Pluto is no longer considered a planet. What will ...

[jho37]

Discuss why Pluto is no longer considered a planet.
 
  What will be an ideal response?

Question 2

Which of the following statements is true of the rings of Jupiter?
 
  A) They must be made of icy material.
  B) They look bright when illuminated from front.
  C) They look light and bluish.
  D) They must be continuously resupplied with new dust.

[sailorcrescent]

Answer to Question 1

In 2006, the International Astronomical Union (IAU) voted to remove Pluto from the list of planets. Pluto is a very small, icy world: It isn't Jovian, and it isn't Terrestrial. Its orbit is highly inclined and so elliptical that Pluto actually comes closer to the Sun than Neptune at times.A bit of comparative planetology shows that Pluto is not related to the Jovian or Terrestrial planets; it is obviously a member of a newfound family of icy worlds that orbit beyond Neptune. These bodies must have formed at about the same time as the eight classical planets of the Solar System, but they did not grow massive to clear their orbital zones of remnant objects and remain embedded among a swarm of other objects in the Kuiper Belt.One of the IAU's criteria for planet status is that an object must be large enough to dominate and gravitationally clear its orbital region of most or all other objects. Eris and Pluto, the largest objects found so far in the Kuiper Belt, and Ceres, the largest object in the asteroid belt, do not meet that standard. On the other hand, all three are large enough for their gravities to have pulled them into spherical shapes, so they are the prototypes of a new class of objects defined by the IAU as dwarf planets.

Answer to Question 2

D