The poem braids two stories into one and lets them blur. One is a stroke: a tear in an artery, a clot, a blockage traveling to the brain. The other is an asteroid landing, with its shadow, its rocky surface, its spin, its pole. The lines never settle on which story we're in. A "blurry image of floating forms" could be a medical scan or a photograph from space, and "a day is about seven hours long inside the bloodstream" folds the two scales together.
The speaker doesn't announce any feeling. The tone is flat, almost like a news report or a science briefing, and that coolness is what unsettles. Phrases like "no one knows why" admit how random and unexplained a stroke can be. The gaps in the lines, and the broken, drifting syntax, mimic a mind losing its thread. The mood is eerie and clinical, with fear sitting just under the calm. The ending, "cutting off a burst / flooding tissue," stops mid-thought, as if the sentence itself has been interrupted.