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 Map and Shapefiles. This map of the United States shows the path of the Moon's umbral shadow â the path of totality â during the total solar eclipse on August 21, 2017, as well as the obscuration (the fraction of the Sun's area covered by the Moon) in places outside the umbral path.