Our galaxy is HUGE. There must be over 200 billion stars out there. The question could be asked is this: DOES LIFE EXIST OUTSIDE OF OUR SOLAR SYSTEM? The simple answer is NO - we have not explored the Milky Way Galaxy, much less sent men into the Solar System. Even though there is nothing precise known, it is still an interesting activity of reducing the POSSIBILITY mathematically. This activity does that. Step by step, the number of possible worlds is reduced for explained reasons. When done correctly, the final answer is that there are 2 planets in the galaxy that perhaps might contain intelligent life.
The first three white pages are intended for duplication and distribution to the class. The last two cream colored pages are the answers for the teacher.
An interesting conclusion the teacher can leave with the class involves two things: (1) If we are are one of those 2 planets, where is the other one, and (2) Could it be possible that the other planet thrived millions of years ago and no longer exists.