A small group watches a rare astronomical event: Venus passing in front of the sun. The poem begins on earth, with a calf wandering up to a fence, other cattle grazing, and cars passing by without stopping. Almost no one notices what is happening overhead. Then the clouds part, and the speaker and the others look through filtered binoculars and see the planet as a dark dot against the sun. "Our size," the speaker says, which makes Venus feel strangely close and familiar.
The mood moves from quiet wonder to a gentle sadness. The speaker knows this won't happen again in their lifetime, and then turns the view around: seen from far away, the Earth would also be one small black spot, turning in space. The closing image of clouds "closing in" suggests how brief and fragile the moment is. The tone is calm and plain, but it carries a sense of how small and fleeting human lives are.