Rebecca Elson was an astronomer whose research involved dark matter—hidden mass which can be inferred only from its influence on observable objects: "As if, from fireflies, one could infer the field." Her poems, too, make inferences and speculate; they set out always from meticulous observation and are not deterred by a knowledge of how little we can know of the universe. A Responsibility to Awe collects her best poetry, along with extracts from her notebooks. The extracts record the ways in which she refined her understanding of "The known human forces, love & hunger, fear and hope—," and explore her own approaching death. An autobiographical essay provides background to her alert imagination, from her upbringing as a geologist’s daughter in Canada to her scientific career around the world.