It seems the bomb also transported the bar to the moon, and created an oxygen field around the bar. Unfortunately, when you leave the bar, you leave the oxygen field. You die of asphyxiation, and the Clangers eat your corpse.
*** You've been
left behind while the world was ending ***
Would you like to cogitate, cogitate a potato, or cogitate this potato of Zork Random? (type RESTART, RESTORE, or QUIT):