There are at least two groups called Planetary:
1) Planet, or Planetary first appeared in the hiphop duo OuterSpace, together with Crypt (Crypt the Warchild).
Here's their Biog.
Outerspace is the brainchild of Philadelphia MC's Planetary and Crypt the Warchild. The philosophy of Outerspace runs much deeper than music; it's literally a family. The two founding members have been friends almost since birth and found a common bond in the music they grew up on such as Gangstarr and EPMD.
The Outerspace vision began to take shape in the early 90's as the duo worked tirelessly to hone the skills that would eventually lead to an alliance with fellow Illadelphians Jedi Mind Tricks and their home-grown label Superegular Recordings. In 1998, Superegular released their debut single We Lyve which was met with critical praise for its complex, scientific rhymes and ethereal, seemingly other-worldly beats.
Outerspace would go on to appear on several JMT tracks and in 1999 the Illegaliens EP was released in on the Wordsound label. Soon thereafter, Outerspace hooked up with DJ SAT ONE and began recording with Jazzy Jeff's production company A Touch of Jazz, This colloaboration proved fruitful with the release of the SAT ONE produced Danger Zone 12' on Soulspazm Records.
2) Planetary is an alias of techno producer Dan Curtin