"Inconstant Moon" is a science fiction short story by the American author Larry Niven. It first appeared in a 1971 short-story collection, All the Myriad Ways. The story won the 1972 Hugo Awards for Best Short Story, and was later adapted into an episode of The Outer Limits television series. Inconstant Moon is also the title of a short story collection published in 1973.


One late night in California, Stan notices the moon shining unusually bright. It continues to grow brighter until it is bright enough to leave an afterimage in his eyes. He telephones Leslie, his girlfriend, and they admire its beauty. After they hang up, Stan, who writes pop-science articles for a living, decides to reason out what is causing the phenomenon. As he realizes the implications, he becomes afraid. He calls Leslie back to invite her out to enjoy what may possibly be the last night of their lives.


"Inconstant Moon" is the quintessential hard science fiction short story; no fantasy elements and taking place in our real world. It is an easy read (if you are unfamiliar with Larry Niven, his writing style is very casual) and short enough to be consumed in one sitting, and yet the story leaves a lasting impression.

What would you do if you found out the world would end in a few hours? What choices would you make? Leslie's choices surprise Stan, and he learns things about her he never knew. There are others out in town, some of whom are aware of the impending doom. Which character would you be?

If you like pop science, you can have additional fun with the mystery aspect of the story by playing “science detective” along with Stan the narrator. If not, you can just take his word for it and enjoy a good story. Great science fiction makes us think about the real world and look into ourselves, and this story definitely does. Gracie A. 5 June 2014

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