Who, or what, crosses over to the United States? The Border Patrol operates this blimp out of Sierra Vista, less than twenty miles from Mexico. Its purpose is officially radar surveillance – the detection of low-flying aircraft smuggling drugs and other cargo. But imagine if the blimp also provided infrared (heat-sensitive) images. It would surely…

Spring is here, though the calendar and a certain groundhog may disagree. In the desert, this time of year is associated with floral blooms. Many species grow and reproduce in these cool months, but only when enough moisture is present. In dry years, many seeds remain ungerminated in the soil; in wet years, growth proceeds…