Abstract:
Before 2004, NASA's Beyond Einstein program included ambitious space missions to understand the nature of the dark energy that has been accelerating the expansion of the universe, test general relativity, and discover gravity waves from the mergers of supermassive black holes and from the cosmic inflation that preceded the Big Bang. All of these, plus space missions to map our home galaxy and investigate whether planets around other stars have life, were indefinitely postponed when President Bush decided in January 2004 that NASA's highest priority is to put astronauts back on the moon and eventually send them to Mars. Under pressure from Congress, the National Academy of Sciences was commissioned in 2006 to report on how to restart the Beyond Einstein program. This colloquium by one of the members of this Academy study, released September 5, will summarize and explain the research strategy the report proposes and its implications for continued U.S. participation in the exploration of the universe.