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.
The solar eclipse of August 12, 2045 will have a very similar path of totality over the USA, about 400 km (250 mi) to the southwest, also crossing the USA's Pacific coast and Atlantic coast; however, duration of totality will last over twice as long.