"It must be ice," said Phoenix Principal Investigator Peter Smith of the University of Arizona, Tucson. "These little clumps completely disappearing over the course of a few days, that is perfect evidence that it's ice. There had been some question whether the bright material was salt. Salt can't do that."
And now the "word cloud," or "wordle," which I was able to create thanks to a link posted by nineweaving:
It began as two paragraphs near the end of Chapter One of The Red Tree. Make of it what you will. Ignore the stray hyphens. I could only link to the thumbnail, without creating some sort of account or another, so screw that. Click the image to see it