Abstract
American astronomers have produced a roadmap that charts their priorities for the next ten years. The report outlines the key scientific challenges over the next decade (see box) and identifies a series of new initiatives that will help to advance our understanding of the universe. The roadmap was produced by a committee of 15 astronomers and astrophysicists set up by the National Research Council. It is the successor to a similar report from 1991 that led to many advances in astronomy during the 1990s.