Mysterious Spheres

These bizarre sculptures have caught the attention of us here at the command center lately. The first is at the Vatican and the second is located outside the United Nations building. Sources say there are up to eight more situated in prominent locations around the world, we have yet to confirm this.
Theories range from a depiction of the planet Nibiru destroying the earth to an image of the the Earth and Moon being consumed in some cataclysm. Investigations continue. Any info on this phenomena is welcome.