eso9861 — Science Release
Distant Supernovae Indicate Ever-Expanding Universe
15 December 1998: Since the discovery of the expansion of the Universe by American astronomer Edwin Hubble in the 1920's, by measurement of galaxy velocities, astronomers have tried to learn how this expansion changes with time. Until now, most scientists have been considering two possibilities: the expansion rate is slowing down and will ultimately either come to a halt - whereafter the Universe would start to contract, or it will continue to expand forever. However, new studies by two independent research teams, based on observations of exploding stars (supernovae) by ESO astronomers  with astronomical telescopes at the La Silla Observatory as well as those of their colleagues at other institutions, appear to show that the expansion of the Universe is accelerating .