Researchers have caught Martian water ice in the midst of a triply amazing disappearing act. Why triply amazing? The ice was spotted amazingly close to the Red Planet’s surface, and amazingly far away from the north pole. The third amazing thing about the observations, made using NASA’s Mars Reconnaissance Orbiter and reported in Friday’s issue of the journal Science, is that the researchers knew it was 99 percent pure water ice because of how slowly it disappeared.