A few examples of what you can ask Wolfram|Alpha about:
compute location and get properties of a moon
compare several moons
display a map of a moon
Properties of Moons
get a property of a moon
compare properties of multiple moons
do computations with properties of planets, moons, etc.
compute the distance to the horizon
get information about lunar phases
find out when a phase will occur
find the moon's phase on a particular date