Space exploration is the act of finding out more about celestial structures. This is mainly done by astronomers using telescopes but it is also achieved by maned and unmanned missions out into the depths of space.
Pros and Cons
We can find other civilizations, which may have more advanced technologies in which we can learn from.
We can learn more about the environment and make scientific advances.
We can find other planets to get their resources.
We might not like what we find and there are hostile civilizations.
People can be killed off of failed manned missions.
We can expend millions of dollars into projects and if they fail money will be wasted.