Encore - Snow Eyes

January 25, 2020

Snow eyes 1

Today and every Saturday Earth Science Picture of the Day invites you to rediscover favorites from the past. Saturday posts feature an EPOD that was chosen by viewers like you in our monthly Viewers' Choice polls. Join us as we look back at these intriguing and captivating images.

Photographer: John Adam
Summary Author: John Adam
Snow eyes inset April 2014 Viewer's Choice Early in March 2014, I took this series of photographs on the way to my office at Old Dominion University in Norfolk, Virginia. There had been a snowfall of an inch or two (2.5-5.0 cm) the previous day and the temperature was a couple of degrees above freezing (32 F or 0 C). I was intrigued by this pattern of eyes in the snow over two very different length scales. The smaller one, the gap between adjacent eyes, was 5-6 in (12-15 cm). There was an electrical power line above from which melting ice could drip onto the road, but it was taut and straight; whereas the position of the eyespots followed the curve of the snow-covered grassy median to a great extent. Furthermore, it's unlikely that the pattern from melting snow would have been so regularly distributed. Paw prints of a one-legged dog, perhaps. Possibly, it was a woman wearing boots with narrow heels; the wet snow might have been thin enough under the sole of the boot to melt more rapidly than around the heel. The cone-like residue from the heel-print is all that remained.

Given the small distance between them, the stride would have been only about a foot long (30 cm); though small mincing steps might have been a result of the person worrying about slipping on ice. But, paw or footprints of some kind would surely be alternatively offset more than they are here, so that doesn’t seem to be a completely realistic explanation. I'm pretty sure it wasn't a clown juggling power tools while wearing stiletto heels. Maybe readers can supply a more convincing explanation. Thanks to Doug Stith, Steve Arcone and Jim Foster for an interesting discussion.

Photo Details: Top - Camera: Olympus SP570UZ; Focal Length: 4.6mm; Aperture: f/5.6; Exposure Time: 0.0040 s (1/250); ISO equiv: 64. First inset - same except: Exposure Time: 0.0031 s (1/320). Second inset - same except: Focal Length: 17.1mm; Aperture: f/5.0; Exposure Time: 0.0050 s (1/200).