The Pantera Nebula is a gaseous nebula which was created several thousand years ago when a type-G star went supernova and pulverized the inner planets of the star system. Certain metals that were contained within the dust made Federation sensors unreliable, and the creation of maps and star charts proved impossible, because the region was in constant flux. In 2372, the USS Enterprise-E and the USS Samson participated in war games inside the nebula. (TNG eBook: A Sea of Troubles)