A man stands on his desert threshold at dusk, looks at the evening star, and ends up mourning the death of his own planet. That is the quiet trick of "Star Cycles," in which Loren C. Eiseley turns a casual act of stargazing into a meditation on how worlds age and die. The poem's central idea is that every planet travels the same road, from young and watery to dry and barren, and that Earth, so comfortably alive beneath our feet, is only further along that road than we like to think.
The opening lines set up the trick with a lovely image: Venus appears as "a dew-gem hung in the western evening," a droplet so small and bright that the speaker can imagine "continents and seas" inside it. He does this "unknowingly," as if his imagination were working ahead of his knowledge. The scale is handled with care. Against the tiny jewel of Venus stand the Joshua trees and yucca of a real, dry landscape, and that detail matters later, because the desert beneath the speaker is already a sample of what is coming.
The poem then folds time into a single sentence. Venus, the speaker says, "must yet run the course of the elements / From stone-breasted saurian down to brain and extinction." The compressed phrase carries the whole of planetary history: reptilian beginnings, the arrival of thinking creatures, and then the ending that follows. Notice that "brain" and "extinction" sit side by side with no pause between them, as though intelligence were merely one stage in the cycle, not its escape. The contrast "she is young—as stars go" adds a faintly wry note, since the speaker is calling a planet young while counting its future in geological catastrophe.
The middle of the poem swings to Mars, and here the imagery turns from jewel-bright to parched. Red sand deserts "creep wider year by year," and the ice-caps offer only a "false / Spring." The word "false" is the sharpest in the passage, since even the hope of renewal is an illusion. The Martians, imagined as "thirst-tortured," look at Earth and see "a sickle of water," a reaping blade made of light, harvesting a "thin harvest of empty sea beds." The sickle metaphor is doing double work: it suggests both water and death, the farmer's tool and the grim reaper's. The phrase "cold sea-wink" is also memorable, giving a distant planet the playful, unreachable quality of a glance across a room. Worship, thirst, and impossibility are packed into a single image.
Then the poem turns back on its speaker, and this is where it stops being science fiction and becomes warning. He calls himself "the first of those deserts which will later / Engulf the whole earth." Through him, we are the Martians in advance. The final lines imagine future people crowded around "our dying ice-cap," gazing from "a myriad housetops" at Venus as a "silver embodiment / Of green woods, and the lost, unforgettable seas." The mirror is complete: what the speaker did on his threshold, they will do on their rooftops, and what he saw in Venus, they will see as an elegy for Earth. The last word, "seas," returns us to the opening image of water, closing the circle the title promises.
Formally, the poem is free verse, without rhyme or a fixed meter. The long, rolling lines give it the unhurried, thoughtful quality of a mind drifting over vast distances, while the indented line "Now, upon Mars" acts like a visual pivot, a pause before the view shifts to another planet. The poem is built on a sequence of "now" moments, past, present, future, so that time itself becomes its main subject.
What makes "Star Cycles" worth reading is its refusal to treat the cosmos as mere decoration. The stars here are not romantic ornaments but a calendar, telling us where we stand. The poem's gift is to make an astronomical idea feel personal: loss, longing, and the beauty of water, seen from a doorstep at dusk.