The song tells of an Earth doomed to destruction in five years and the aftermath of this knowledge. Bowie is rumored to have chosen the length of time, five years, as a result of a dream in which his deceased father told him he must never fly again and would die in five years.
Allmusic describe the track as "easily one of the greatest album-opening songs ever".
The track was performed by Bowie with Arcade Fire at the 2005 Fashion Rocks concert in New York as well as "Life On Mars?" and Arcade Fire's own song "Wake Up". These recordings were made available on the iTunes Music Store in a virtual live EP.
The track was to be the closing number of David's 1985 Live Aid set at London's Wembley Stadium but was dropped the day before the concert to allow time for the broadcast of the famous appeal video featuring "Drive" by The Cars as its soundtrack.