SNAP (SuperNova/ Acceleration Probe) is a satellite experiment designed to verify the remarkable cosmological discovery that the Universal expansion is accelerating, and to determine the nature and evolution of the “dark energy” driving this acceleration.  Recent measurements carried out by the Supernova Cosmology Project (SCP) and the High-Z Supernova team have made the startling discovery that the expansion of the universe is accelerating.   The SNAP mission is expected to provide an understanding of the mechanism driving the acceleration of the universe. The satellite observatory will be capable of measuring up to 2,000 distant supernovae each year of the three year mission lifetime. These measurements will map out in detail the expansion rate of the universe at epochs varying from the present to 10 billion years in the past.  SNAP will determine the spatial curvature of the universe, thus providing a fundamental test of the theory of inflation - the theoretical mechanism that drove the initial formation of the universe.  Like its ground-based predecessors, SNAP uses type Ia supernovae as astronomical standard candles to provide a distance scale, which, combined with the redshift obtained from the spectral lines from the supernova and its host galaxy determine the cosmological parameters and ultimately the nature of the "missing energy" in the universe.  

For more information about SNAP, visit its home page here Other Links of Interest Physics Today article describing recent events in the field Supernova Cosmology Project Home Page High Z SN Search Home Page