Planet gun

One of the most powerful superweapons known, the Planet gun can essentially turn planets into giant warships capable of destroying unshielded celestial objects.

Tethys
This moon of Saturn was the first, and only, celestial body to be outfitted with a Planet gun. It was tested by destroying the moon of Mimas. The test was succesful, utterly vaporising the moon, leaving behind only a few pieces of debris, no more than ten meters wide. Several physicists proposed the use of Shey propulsion technology to make the planet a literal warship, capable of moving where ever it was needed, rather than being restricted by its orbit around Saturn. The Human council turned down the proposition because of its massive budget required to complete, and instead outfitted every planet under Human control with a Planetary shield.