is it possible for planets to fall out of orbit?

Question: is it possible for planets to fall out of orbit?
- Keywords:
  orbit,
  planet
Asked by spacegirl to Anne, Beth, COLFlight, Jon on 15 Oct 2015.
- Beth Healey answered on 15 Oct 2015:
  
  Hey spacegirl!
  
  Yes it would be possible if they were hit by an object with sufficient energy! For example, another planet.

Question: is it possible for planets to fall out of orbit?