Moon: Hit it with a Nuke?

One Time America Thought About Nuking the Moon and In 2010 Did Hit it With a Rocket

The 1950s were a bizarre period in American history. An economic boom brought joy to a generation home from war while a strange level of distrust lingered, of enemies both internal and external, in a nation not quite at war, but not quite at peace either. Technology was advancing in leaps and bounds, and the Space Race between the United States and the Soviet Union was underway. To America’s dismay, the Soviets were winning – at least at first.
However, before humans set foot on the moon and America relaxed into self-declared victory, the U.S. seriously considered a surprising plan. The military wanted to nuke the moon. It was a very tiny nuke; only a tenth or so the size of bomb America dropped on Hiroshima. The 1950s saw hundreds of nuclear test explosions on Earth by the American, Soviet, and British governments. The moon’s remote location and lack of inhabitants makes it an almost sane choice by comparison. And while THAT plan never came to fruition, humans have actually blown up the moon’s surface a handful of times. [..snip] 
The plan from 1958 didn’t have either of those benefits. Designers conceived the plan largely to boost America’s ego over the space race it was in the midst of losing to the Soviet Union, not for any real scientific value. And it would have definitely contaminated the moon’s surface for future investigations. [..] Strangely enough, the Soviet Union may have considered nearly the same nuclear plan, for largely the same reasons: in their case, to prove and maintain their superior stance in space.
Luckily, cooler heads prevailed on both sides.

Man's Quest to Learn God's Secrets: Explode Stuff in Heavens
On October 9, 2010, NASA strike on the moon kicked up enough dust for scientists to determine whether or not there is water on the moon. NASA’s LCROSS mission successfully bombed the moon [it failed to produce the promised live photos however].

First: a 2.2-ton empty rocket hull smacked the moon’s south pole
Then four minutes later: the camera-and-instrument laden space probe made its death plunge. Centaur rocket was expected to transform 2200 kg of mass and 10 billion joules of kinetic energy into a blinding flash of heat and light. Researchers expect the impact to throw up a plume of debris appx 6 miles high. Reportedly they found water. [Cost? many billions of dollars.] More here and here