Haloes over VISTA

Haloes are optical phenomena produced by light interacting with ice crystals suspended in the atmosphere. Light is reflected and refracted by the ice crystals and may split up into colours because of dispersion. The crystals behave like prisms and mirrors, refracting and reflecting light between their faces, sending shafts of light in particular directions. Here solar haloes are clearly visible above the enclosure of VISTA on Cerro Paranal.