eso8710 — Science Release
Is the Universe Younger than Previously Thought?
3 July 1987: The first observations of a long-lived radioactive isotope outside the Solar System indicate that the Universe may be younger than previously thought. Using one of the world's most powerful spectrometers, located at the ESO La Silla observatory in Chile, Professor Harvey R. Butcher of the University of Groningen, The Netherlands, has detected for the first time the radioactive element Thorium-232 in stars. A comparison of its abundance in old and young stars failed to show the expected differences. This means that the total age of Thorium-232 in these stars must be smaller than about 10 Gyr , instead of the previously estimated 16 - 18 Gyr.