Acheron

Leading from

Aliens

a) The Name of the planet
James Cameron named the unknown planetoid from Alien as "Acheron". Prevue stated in a question to him that Acheron was a name Dante used in his description of the Ninth Circle of Hell and also in an interview to be identified,  Cameron states that he believed that Acheron a feature in the ninth circle of Dante Alighieri's Hell. He thought that it might be the sort of thing that a colonist who had an interest in literature might have named the place. 

b) Idea about the planet
James Cameron had the idea that the planetoid was a raw primal world constantly windswept with freezing rain, and unlike Earth except for certain familiarities such as clouds and mountains 

c) Further thoughts about the name
The name Acheron came from one of the five rivers in Hades that were the tributeries of the river Styx from Greek mythology. Meanwhile Homer wrote that Acheron was described as a river of Hades, into which Cocytus and Phlegethon both flowed.  In James Cameron's mind, it was a frozen swamp

Quote Sources

1. Prevue: The conflict takes place on Acheron, a name Dante used in his description of the Ninth Circle of Hell. What's your vision of the alien planet?
   Cameron: A raw primal world constantly windswept with freezing rain - unlike anything on Earth, except for certain familiarities, like clouds and mountains. The colours, the light, the contours, everything so harsh and hostile that even the rock formations have been eroded into tortured shapes, all dark and shadowy so that things sometimes appear to be there - even when they're not.  (Prevue August 1996, p42-46/ and later reprinted in James Cameron: Interviews, edited by Brent Dunham)
2. Interviewer: When you went about creating the world of Arceon
   Cameron: Acheron
   Interviewer: Acheron
   Cameron : Right
   Interviewer: Um, the
   Cameron: Which which by the way is a feature in ... in the ninth circle of Hell I believe,    in Dante Alighieri’s Hell, it's a frozen swamp
   Interviewer: Is that where the original concept... is that the original name of the planet in the original
   Cameron: No, no, no, there never was a name for the planet in the original film so I made up.. made one up.... which seemed to be the sort of thing that some... some... sort of poor colonist who had a literary bent (chuckle) might have named the place. It's... it's... it's a raw and primal world, wind swept, not a place you'd want to live, cold, freezing rain, that sort of thing, I wanted to... to do two things, I wanted to say this is definitely unlike anything that exists on Earth, but with points of familiarity, mountains, clouds, rain, that sort of thing, and using that, create a sensation, not of something that's absolutely inhuman and bizarre but just of a place that's very difficult to survive in and the idea that the... the colonists that live there are like, er, are like pioneers, in a, in a, in a very very unforgiving climate, and erm, they they work very hard to get a tow hold, and it it it all gets very upset by the erm, well, by the erm situation in the plot, (chuckle) which I wont go into, but er, I want it to be in every, every line, every every bit of lighting, colour and everything, just to be incredibly hostile, wind, lightning , rain, these tormented rock forms that are.. are.. eroded by the wind into strange shapes, and then it's all very dark and shadowy, and when you look at these shapes, sometimes you see things that aren't there, you know, that's the idea anyway, and we'll see what we'll come up with. (Interview taken from the Alien Anthology blu-ray capsules,  conduted at the time of the film's release 1986)
3.  "'You will want no guide,' she (Circe) answered; 'raise your mast, set your white sails, sit quite still, and the North Wind will blow you there of itself. When your ship has traversed the waters of Oceanus, you will reach the fertile shore of Proserpine's country with its groves of tall poplars and willows that shed their fruit untimely; here beach your ship upon the shore of Oceanus, and go straight on to the dark abode of Hades. You will find it near the place where the rivers Pyriphlegethon and Cocytus (which is a branch of the river Styx) flow into Acheron, and you will see a rock near it, just where the two roaring rivers run into one another." {Homer's The Odyssey)