View of the Martian probe on the frost-covered surface looking southeastViking Lander, 25 September 1977Vintage chromogenic print on resin-coated Kodak paper, 25.4 x 20.3 cm (10 x 8 in), (NASA/Jet Propulsion Laboratory)Footnotes:This photograph from the Viking Lander 2 shows late-winter frost on the ground on Mars around the lander. The view is southeast over the top of Lander 2 and shows patches of frost around dark rocks. The studies of ice and frost, and its disappearance over prolonged periods of time became an important factor in investigations of the existence of water on Mars