A planet located in the Arkula System of Sector Theta that has an atmospheric composition and surface gravity approximately identical to those of Earth. The planet's atmosphere is tinted a deep emerald color.
This naturally beautiful world is currently enjoying a period of stability, but at one point in its past the high density of Energy Stones distributed throughout its atmosphere polluted the entire planet. This mysterious pollution, which began in 366 SD, continued for several years, and affected the psyches of many of the planet's wild animals, causing them to ferociously attack the native Expellians. However, in 371 SD, Dr. Neuyman succeeded in developing his Neuyman Purifier, a device that was able to remove this pollution. This cleaner worked wonderfully, removing most of the pollution by the very next year, and thereby eliminating almost all of the negative influence of the Energy Stones. Recognizing the value of this technology, Expel was invited to join the Pangalactic Federation at the end of the same year.
Because Expel is one of the few planets that generate Energy Stones - a necessity in the creation of Quadratic Keys - the planet is an extremely influential voice within the Pangalactic Federation.