Radiant Horizons

The stars and dust lanes of the Milky Way hang above telescope domes in this richly hued image of Cerro Tololo Inter-American Observatory (CTIO), a program of NSF NOIRLab. The two bright, wispy ovals to the right are the Large and Small Magellanic Clouds, dwarf galaxies visible only in the southern hemisphere. The band of color along the horizon is a phenomenon known as airglow, a visible reaction between molecules in Earth’s atmosphere and solar radiation. In this picture are the Curtis Schmidt Telescope (left), the Víctor M. Blanco 4-meter Telescope (middle), and the SMARTS 1.5-meter Telescope (right). These telescopes, alongside 12 others, comprise CTIO, the principal ground-based optical platform for US astronomical investigation of the southern skies.