Discuss why astronomers no longer consider Pluto a planet. ...

[imowrer]

Discuss why astronomers no longer consider Pluto a planet.
 
  What will be an ideal response?

Question 2

What observations suggest that Triton has had an active crust?
 
  What will be an ideal response?

[Swizqar]

Answer to Question 1

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 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 enough to clear their orbital zones of remnant planetesimals and consequently remain embedded among a swarm of other objects in the Kuiper Belt.

Answer to Question 2

By counting craters on Triton, planetary scientists conclude that the surface has been active as recently as a million years ago and may still be active.

[imowrer]

Excellent

[ryansturges]

Gracias!