Vega Island, off the Antarctic Peninsula, has again displayed an ice formation whose outline resembles a skull. Photographed from the air, the image combines a dark cavity suggesting eye sockets with an irregular ridge mimicking a jaw, so the whole produces an unsettling impression at first glance.

It is one more example of pareidolia, the tendency of the human visual system to recognise faces and familiar figures in random patterns. In glaciers and sea ice, wind, ice sublimation and summer melting carve cracks, caverns and ridges that, seen from a certain angle, take on recognisable shapes. Vega Island, facing the Antarctic Peninsula, is well suited to such natural sculptures.

Beyond the visual effect, formations of this kind are useful to glaciologists: the position and evolution of cracks and caverns through the seasons allows them to track ice dynamics and the effects of regional warming. The image, released by NASA, does not by itself describe changes in the ice front, but illustrates the kind of features that satellites and reconnaissance flights routinely map in Antarctica.