The process in which the anatomical structures of an aorta are generated and organized. An aorta is an artery that carries blood from the heart to other parts of the body. [ GOC:bf GOC:dgh http://www.informatics.jax.org/searches/AMA.cgi?id=MA:0000062 http://en.wikipedia.org/wiki/Aorta http://purl.obolibrary.org/obo/UBERON_0000947 ]