Inconstant Moon is a science fiction short story collection by American author Larry Niven that was published in 1973.

He then calls and visits his girlfriend Leslie, presuming her ignorant of the situation, but she realizes it independently when Jupiter brightens with appropriate delay; they then enjoy their last night on the town, before rain and winds start.

The story ends at the break of an overcast, gray morning, with Leslie's apartment becoming an island among the raging flood waters, but with the narrator rather optimistically wondering "if our children would colonize Europe, or Asia, or Africa."

Jo Walton in 1997 wrote a short poem, "The End of the World in Duxford",[1] as "an unauthorised version of 'Inconstant Moon', a British equivalent.

In orbit around the world, they notice that one of the continents has a thin, strange border all the way around its coastline, which radiates a low heat and appears black in visible light.

Muller, a smuggler with a cargo of precious magnetic monopoles, attempts to use Mars (the 'hole' of the title; to spacers, planets are merely gravity wells to be avoided if possible) as a means to whip his ship to a new orbit that will enable him to escape the customs authorities who are chasing him.

The two Mars stories do belong to "Known Space" and they are specifically referred to and to some degree influence the plot of Protector, which takes place a long time later.

Also, the failure of Mars colonization as depicted here contributes to the generally held opinion in that future history that planets (at least in the Solar System) are virtually worthless and it is asteroids which are the truly desirable real property.

[5] During a routine hyperspace jump, an accident involving a small meteoroid striking into the machinery causes the ship to be trapped in a stasis until billions of years have passed.

Reluctantly, believing that any other similarly senescent star will offer no better option, the people accede to the new captain's order to land on Earth despite the lack of an atmosphere.

About to return to Earth, Eric reveals that something is wrong with the ramjet that propels the craft, necessitating a landing in order to fix the problem.

He believes Eric has a psychosomatic disorder preventing him from operating the ramjets, using the analogy of a traumatized soldier who can no longer feel his hand and pull the trigger of a gun.

Asteroid miner Owen Jennison is found dead in an apartment on Earth, apparently of suicide: He was a wirehead, directly stimulating the pleasure center of the brain, and starved.

Eventually, Gil is captured by the organlegging gang, until, under threat of being harvested alive for his organs, his "third arm" - a psychologically limited form of psychokinesis – allows him to kill his captor in spite of being completely bound.

The title, a play on the tradition of murder mysteries, is a reference to the story's investigators speculating about the experience of being electrocuted through the pleasure centre of the brain: Had his death been momentary Hell, or all the delights of paradise in one singing jolt?

[7] The story is part of the “Known Space” series, where the political and cultural differences between Earth humans and those of the asteroid belt are an important recurring theme.

It is one of a group of Known Space stories in which Niven speculates on the effect on human culture of simple universal organ transplants: Every voter had a bit of the organlegger in him.