Hydra, the Largest Constellation

The constellations of the northern hemisphere’s spring nights roar the sky in this wide-field image from a dark desert in central Iran. Winter constellations set in the west above the light dome of nearby city Kashan. The lines show the largest constellation in the sky, a celestial snake known as Hydra. This ancient constellation spans over 90 degrees from the head to the tail and covers 1303 square degrees of the sky.