7 January 2009: Kenneth Libbrecht, a professor of physics at the California Institute of Technology, has been studying snowflakes, ice patterns, crystal growth and ice formations since 1997. He faced sub-zero temperatures to catch falling snowflakes and photograph and illuminate them using a specially designed photo-microscope. These pictures show snow crystals that fell to earth in Northern Ontario, Alaska, Vermont, the Michigan Upper Peninsula and the Sierra Nevada mountains of California, and are showcased in his Snowflakes book