Exoplanets challenge the notion that we are alone in the universe. Learn what types of exoplanets exist, the methods scientists employ to find them, and how many worlds might exist in the Milky Way Galaxy. 

QUESTIONS: 

1. What are Exoplanets? Enumerate their four classifications. 

2. How come extrasolar planets are difficult to detect? Specify five methods to find these said planets.

3. What interesting fact do you know about our solar system?