Icy starbursts

It was eight degrees below freezing yesterday morning on the maximum-minimum thermometer, and today's reading was even lower—18 at the turnaround. How cold was it? Ah, that is always the back-country discussion-starting query. The quick answer was that it was cold enough to cause the rhododendron and fern leaves—all evergreen—to roll, a freeze-prevention strategy botanists call thermonasty. It was also cold enough to make a hat, gloves, and a heavy jacket mandatory on my walk, and as I headed downhill, I had a sneaking suspicion that the Big Chill had worked some artistic magic at the millpond. On that last count, I wasn't to be disappointed. The frost was heavy on the remaining leaves, and the shallows had grown a thin sheet of ice in the overnight hours. In places, there were starbursts... well, icebursts... curiosities that are wonderful to capture, but perplexing: how and why do these form? And where can I find an ice development researcher to ask? Documenting the natural world brings with it a never-ending supply of discoveries... and questions.