This picture of Comet Hyakutake taken the night of March 21/22 in Illinois, USA shows the enormous tail that has already developed. The silhouette on the right is a foreground tree, and the superposed green circle on the left shows the size of the full moon.

Sometimes falling ice crystals make the atmosphere into a giant lens causing arcs and halos to appear around the Sun or Moon. This past Saturday night was just such a time near Madrid, Spain, where a winter sky displayed not only a bright Moon but as many as four rare lunar halos.

A dark river seems to flow through this sky from the horizon toward colorful clouds near red giant star Antares. Murky looking, the dark river is a dusty nebula obscuring background starlight near the central Milky Way, although the dark dust nebula contains mostly hydrogen molecular gas.