A tall shadow is cast over the world as a Ukrainian child helps to draw a chalk picture of the earth during a public environmental awareness project to mark international Earth Day, in the capital city of Kiev, Saturday, April 22, 2006. On April 26, the world will mark the 20th anniversary of the explosion at the Chernobyl nuclear power plant, which sent radioactive cloud across Europe and was the world's worst ever nuclear accident. The writing reads in Russian ''our world is unique''.(AP)