On the night of Jan. 9, 2019, the V. M. Blanco 4-meter telescope at the National Science Foundation’s (NSF) Cerro Tololo Inter-American Observatory (CTIO), high in the mountains of Chile, will close the camera’s shutter on the final image from the Dark Energy Survey (DES) — a survey that has mapped 5,000 square degrees of the heavens, almost one-quarter of the southern sky.