As part of 'Time Travel' week, we take a trip back 40 years with a song about a "space invader" by rock chameleon and musical genius David Bowie. 'Moonage Daydream' originally came out as a single in 1971 and appears on Bowie's classic 1972 album 'The Rise and Fall of Ziggy Stardust and the Spiders From Mars.'

Bowie initially released 'Moonage Daydream' via his short-lived Arnold Corns side project. The tune was paired with the B-side 'Hang on to Yourself.' After the single failed to gain any commercial success, he reworked the lyrics to 'Moonage Daydream' and included it along with 'Hang on to Yourself' on the 'Ziggy Stardust' album.

The concept of 'Ziggy Stardust' centers on an alien being who takes on the messianic role of a rock star during the last five years of Earth's existence. 'Moonage Daydream' serves as an introduction of sorts to the Ziggy Stardust character, the common thread between all the songs on the album.

It's a metaphorical tune that details the deviant and rebellious nature of Ziggy Stardust: "I'm an alligator / I'm a mama-papa coming for you / I'm the space invader / I'll be a rock 'n' rollin' bitch for you."

The chorus portrays Ziggy as a sexually free alien rock god with little inhibition: "Keep your 'lectric eye on me babe / Put your ray gun to my head / Press your space face close to mine, love / Freak out in a moonage daydream"

The song also blurs the lines between religion and romance with the lyrics "Don't fake it baby / Lay the real thing on me / The church of man, love / Is such a holy place to be."

While not a major hit for Bowie, 'Moonage Daydream' is one of his most dynamic songs. It offers the stirring combination of Mick Ronson's powerful guitar playing and Bowie's mysteriously intriguing lyrics.

In 2002, Bowie released a book called 'Moonage Daydream: The Life and Times of Ziggy Stardust,' which included photos and personal memoirs from the years 1972-1973.

Watch David Bowie Perform 'Moonage Daydream'