A substance is anhydrous if it contains no water, for example, salts lacking their water of crystallisation. The way of achieving the anhydrous form differs from one substance to another.
A partial solar eclipse at its peak at 3:37 p.m. in Mesa on Oct. 23, 2014. The eclipse was visible over most of North America and covered 44 percent of the Arizona sun. Michael Chow/The Republic.
2017 Total Solar Eclipse. August 21, 2017 Total Solar Eclipse Across the United States. On Monday, August 21, 2017, the contiguous United States will experience the first total solar eclipse since February 1979 when it was visible only in the Pacific Northwest!