Is there any difference between natural and man-made snow? If there is, what is it and what impact does it have on winter athletes?

If you're watching the Winter Olympics, you know, of course, that snow and ice are an integral part of the sports. There just wouldn't be a Winter Olympics without it. But did you know that snow and ice need to be different for each different sport? NASA scientist Peter Wasilewski's studies of ice using polarized light create beautiful colored pictures of the snow and ice, but they also enable people to see if the snow and ice is "right" for each type of sport.

Wasilewski, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Md. uses polarized light to see the colors in the ice crystals that make up the ice and snow. Light has wave-like properties, one of which is vibration. Ordinary white light vibrates in many directions, but a polarizing filter blocks all light except that which is vibrating in a single direction. For example, when light reflects off nonmetallic surfaces such as glass, water, or a road surface, the light is polarized, or just vibrating in one direction. Unpolarized light like the light emitted by the sun, by a lamp in the classroom, or by a candle flame goes in all directions.

The colors and patterns in the images produced by using the polarized light define the type of ice and snow being studied. A core from an ice rink that had been recently skated on would show multi-colored granules, like snow dust, created from the sharp blades of the skates cutting into the ice. Below that would be what appears to be vertical and cylindrical ice crystals that extend to the next layer of ice, which is usually a surface painted white in an ice rink. Below that would be another two vertical layers of multi-colored crystals.

"Ice is different for the various Olympic sports," Wasilewski said. "The ice is softer for figure skaters than it is for hockey players. Figure skaters need to dig in with their toe picks for jumps. Ice hockey players want the hard ice that makes the ice fast and easier to skate on. With a microscopic look at the ice using the spectrum, I'm able to see how the ice differs."

It is also fascinating to learn about the highly technical nature of maintaining the ice arenas at the Olympics games. Since the ice is used for different venues at different times, it's important that it be the correct consistency for the sport, and that means careful analysis by the crew to either heat up or cool down the ice so that it matches what is needed to bring out the best performance by the Olympians.

Wasilewski also knows a lot about snow and the Olympics. He noted that snow that comes from snow guns are not in crystal shape, they're tiny snowballs. In fact, he said that sometimes Olympic events are cancelled whenever there is a lot of natural snow, because it tends to be too powdery. Powder snow tends to slow skiers and snowboarders down, so the preference is for the manmade (icier) snow.

Wasilewski traces his interest in ice and ice photography to his friend, Dr. Tony Gow, formerly of the U.S. Army's Cold Regions Research and Engineering Laboratory, now retired. "Tony Gow spent 45 years studying ice, and is a world-class expert. He was fascinated by how much he could learn just from the shapes and colors in ice. His enthusiasm was infectious, and I became fascinated as well," said Wasilewski. He has been fascinated with snow and ice for more than 25 years, and has been on 6 Antarctic expeditions over that time. He later developed a winter camp in Lake Placid, New York, former home to a winter Olympics of 1932 and 1980, to teach snow and ice science to science teachers. His camp is called "The History of Winter," which is in part funded by a NASA education program.

During one of his treks to Lake Placid he sampled ice at the shallow Cascade Lake. A thin section revealed petal shaped ice forms that were the result of a spiral growth pattern induced by the bubbling of methane gas that was produced by the decay of submerged vegetation present when the ice froze. At that moment, he realized that color and form could change depending on the thickness and orientation of the ice. "I started playing around, making ice crystals in my refrigerator and photographing them, and 'Frizion' was born," said Wasilewski.

The derivation of the name "FRIZION" is a fusion of frozen and vision that describes this new art form. Each piece begins as a vessel of water which is then frozen, manipulated and viewed through polarized light - the resultant image, after much trial and error, becomes a FRIZION. The special crystallographic and optical properties of ice (transparency, double refraction, and an amazing variety of crystalline forms) make it a unique medium for artistic studies.

Right now, things are looking very good for the Americans at the 2006 Winter Olympics in Torino, Italy, and if Peter Wasilewski has anything to do with it, the athletes will be skating on thin ice (or is it thick ice?) well, it's whatever ice they need to perform their best and hopefully win one of those elusive medals. Would that be a miracle on ice? To quote a favorite writer of Wasilewski's, "If there is magic on this planet, it is contained in water"…Loren Eiseley." Not a miracle, just magic.

His snow and ice studies fit perfectly with the upcoming International Polar Year, which runs from 2007 to 2008.

For information about the artwork of Frizion, please visit on the Web: http://www.frizion.com

For a related story, please visit on the Web:
http://www.nasa.gov/centers/goddard/news/topstory/2003/0508ice_photo.html

For information about the "History of Winter" science camp, visit on the Web:
http://education.gsfc.nasa.gov/prehow2005 or
http://www.historyofwinter.org

This week's question comes from Rob Gutro. Rob is a meteorologist who works at NASA Goddard in Public Affairs. He did forecasting for the Weather Channel Radio Network, was a technical writer for NOAA, provided broadcasts on NOAA Weather Radio in Baltimore, and was a radio personality for 20 years in various cities.