Actor William Shatner is hitting the road with prog-rock supergroup Circa to promote his new album of sci-fi music. Former Yes stars Billy Sherwood and Tony Kaye will back the Star Trek legend when he tours following the release of his first progressive rock album Ponder the Mystery. Sherwood actually helped the actor create the music for his poems, which make up the tracks on the album. The project also features guest spots from another former Yes star, Rick Wakeman, Vince Gill, Steve Vai, The Doors' Robby Krieger and Mick Jones. And Shatner tells RollingStone.com he's really proud of his latest musical venture: "I'm learning to play the album now as we prepare for the live performances. The more I play it, the more I hear the musical overtones, the more impressed I am about my own album."