Evolution of the Venera 13 imagery

There are indications that the spacecraft may have changed its position slightly 50 min after the television cameras began to operate. Material which was spread over the landing ring of the spacecraft did not remain stationary. Wind is considered the most likely cause of the movement. Attention is called to the fact that the contrast of individual features tended to change with time. This affected both parts of the spacecraft and objects on the surface of the planet. It is suggested that this may derive from variability in the type of illumination, brought about, for example, by the motions of cloud formations in the atmosphere.