Very relaxing track produced by kind of a trance music legend Chicane, inspired by 'Hoppipolla' from Sigur Rós. Personally I love the melody starting at 1:27.
Ripped from TATW 268. Enjoy.
Wallpaper link: http://isidora.deviantart.com/art/Heartbeat-of-the-Earth-70868926
Many people asks about it.