Acid precipitation, also known as acid rain, is any form of precipitationâ€”snow, rain, sleet, or hailâ€”that contains a heavy concentration of sulfuric and nitric acids. Automobiles, certain industrial operations, and electric power plants that burn fossil fuels emit pollutants that combine with atmospheric moisture to create these acids. Acid rain can contaminate drinking water, damage vegetation and aquatic life, and erode buildings and monuments. Where was acid rain first found?
Back in the day
In 1513, Spanish explorer Juan Ponce de LeÃ³n set out from Puerto Rico, sailing northeast through the Bahamas. He soon sighted the Florida peninsula, which he believed was actually an island, and in early April, he became the first European to reach it. His discovery coincided with the Easter feast, Pascua Florida, and is perhaps the reason why he named the land he claimed for Spain "La Florida." What legendary site do many believe the explorer was searching for when he found Florida?
Born on a day like today
Ernst was a German painter who joined the Dada movement in Paris after WWI and later became one of the founders of surrealism. He experimented with collage, photomontage, and surreal images, creating some of the most haunting images of 20th-century art. An innovator as well as a painter, Ernst developed several artistic techniques, including frottage, in which the artist rubs a drawing tool against paper that is laid over a textured surface, and grattage, a technique consisting of what?