Arne Kersting, member of the ArTTA working group, prepares a block of ice, which is a probe from Austria's Schaufelferner glacier, for the Argon-Preparation-System at the Institute of Environmental Physics in Heidelberg, Germany, December 6, 2018. Atom Trap Trace Analysis for 39Ar is an ultra-sensitive detection method based on principles of quantum mechanics. Scientists extract Argon, a Noble Gas, from the air bubbles trapped in the ice. After the extraction, scientists catch and count the rare Ar39 atoms to determine the age of the air and in result the age of the ice. REUTERS/Lisi Niesner