There are multiple artists called "Planetarium".
1) A progressive italian rock band in the early '70. Their most important Lp is "Infinity" realised in 1971, a concept album about man's life.
2) The musical endeavours of Pete Namlook (aka Air, Syn) and New Composers. Upbeat techno invoking spacial imagery; distant noise emanating from the depths of the galaxy. Intricate beats and catchy basslines. As close to "conventional" as Namlook ever went - and not even close!