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.
April 18, 2017. The next total solar eclipse visible from the continental United States occurs August 21, 2017. Itâs likely to be the most-viewed ever, so the time to start planning where you will be on that date is now.