This is a scientific experiment aimed at furthering manned Lunar missions.. The details have been available for months. It is not new news. Go to spaceweather.com for past articles and links to sites for continuing live coverage during the impacts. The experiment may or might not be successful, but in no case is it a test of weapons.
The plume thrown up by the impacts might be visable from Earth, but only if you have a telescope capable of at least 500x magnification.

The craters have been chosen carefully for maximum potential of finding water. Viable outposts at the lunar poles would be a vital step in humans moving out into space. Since we seem to be incapable of reducing our population this has to be done if there is any chance of avoiding the eventual destruction of the huamn race as we outgrow our home world. (6.8 billion and counting.)

The impacts will not change how the moon looks in the least. In fact, they are laughable small compared to the emormous rocks that changed to moon into our familiar ance scarred co-planet.