We've seen a lot of snow over the last few weeks in both the U.S. and Canada.  But snow that doesn't melt when held to a blowtorch or lighter? Videos of this strange phenomenon went viral last week.

However, as Johanna  Wagstaffe explains in this week's Science Smart, there's a perfectly reasonable explanation. 

If you have a science question you'd like answered, send Johanna Wagstaffe a tweet (@JWagstaffe) or an email to Johanna.Wagstaffe@CBC.ca.