*Description*: These are images of three of the most distant supernovae known, discovered using the Hubble Space Telescope as a supernova search engine. The stars exploded back when the universe was approximately half its current age. The light is just arriving at Earth now. Supernovae are so bright they can be seen far away and far back in time. This allows astronomers to trace the expansion rate of the universe, and to determine how it is affected by the repulsive push of dark energy, an unknown form of energy that pervaded space. The research team members are: Adam Riess and Louis-Gregory Strolger (STScI), John Tonry (Univ. of Hawaii), Stefano Casertano, Harry Ferguson and Bahram Mobasher (STScI), Peter Challis (Harvard-Smithsonian Center for Astrophysics), Alex Filippenko, Saurabh Jha, Weidong Li, Ryan Chornock (Univ. of California, Berkeley), Robert Kirshner (Harvard-Smithsonian Center for Astrophysics), Bruno Leibundgut (European Southern Observatory), Mark Dickinson, Mario Livio and Mauro Giavalisco (STScI), Charles Steidel (Caltech), Txitxo Benitez and Zlatan Tsvetanov (Johns Hopkins Univ.). Technical facts about this news release: About the Data Data Description: The datasets used for these results are from the HST programs: 9425 and 9583: Great Observatories Origins Deep Survey (GOODS) 9352: A. Riess (STScI), J. Tonry (Inst. for Astronomy, Univ. of Hawaii), M. Dickinson (STScI), C. Steidel (Caltech), A. Filippenko and W. Li (UC Berkeley), R. Kirshner (Harvard College Obs.), S. Jha (UC Berkeley), P. Challis (Harvard College Obs.), and S. Casertano (STScI). The science team consists of: A. Riess and L.-G. Strolger (STScI), J. Tonry (Inst. for Ast./U. Hawaii), S. Casertano, H. Ferguson, and B. Mobasher (STScI), P. Challis (Harvard College Obs.), A. Filippenko, S. Jha, W. Li, and R. Chornock (UC Berkeley), R. Kirshner (Harvard College Obs.), B. Leibundgut (ESO), M. Dickinson, M. Livio, and M. Giavalisco (STScI), C. Steidel (Caltech), T. Benitez and Z. Tsvetanov (JHU). Program: 9352: A. Riess GOODS (HDF-N) GOODS (HDF-N) Instrument: ACS and NICMOS ACS/WFC ACS/WFC Exposure Date(s): Sept. 2002 - June 2003 Nov 2002 - May 2003 July 2002 - Feb 2003 Filters: ACS: F775W ("i"), F850LP ("z"); NICMOS: F110W (J-band), F160W (H-band) F435W ( "B "), F606W ( "V "), F775W ( "i "), F850LP ( "z ") F435W ( "B "), F606W ( "V "), F775W ( "i "), F850LP ( "z ") About the Image Image Credit: NASA and A. Riess (STScI) Release Date: February 20, 2004 *News Release Number:*: STScI-2004-12a