 Many physicists knowledgeable about the origins of the field of astroparticle physics prefer to attribute this 'discovery' of cosmic rays by Hess as the starting point for the field.While it may be difficult to decide on a standard 'textbook' description of the field of astroparticle physics, the field can be characterized by the topics of research that are actively being pursued.The journal "Astroparticle Physics" accepts papers that are focused on new developments in the following areas