Anna Von Mertens' thoughtful new exploration of Henrietta Swan Leavitt's life describes and illuminates Leavitt's decades-long study of stars, including the groundbreaking system she developed for measuring vast distances within our universe simply by looking at photographic plates. Leavitt studied hundreds of thousands of stars captured on the glass plates at the Harvard College Observatory, where she worked as a human computer from the turn of the 20th century until her death in 1921. Von Mertens explores her life, the women she worked alongside, and her discoveries, weaving biography, science, and visual imagery into a rich tapestry that deepens our understanding of the universe and the power of focused, methodical attention.