Q.R. Quasar describes a galaxy supercluster as a kind of cosmic graveyard, comparing it to the Sargasso Sea, a stretch of ocean where ships were said to drift and stall. Here, galaxies pull together by gravity but have no fresh gas left to form new stars. The poem treats this as a slow starvation: the galaxies lose their "flesh" of gas, shrink down to "galactic bone," and either fling off what remains or let central black holes swallow it.
The tone begins almost like a science report, calm and factual, then turns personal. In the final lines the speaker drops the technical language and asks, again and again, "ain't it cold?" The question seems to blur the distance between the galaxies and the speaker, as if the cold belongs to "in here" as much as "out there." The broken, trailing rhythm of "oh...so... slowly... the lights" mimics fading out. The mood is lonely, hushed, and quietly mournful.