Studying sandrock (IMAGE) University of Groningen Caption Johannes Miocic (left) and PhD-student Sebastian Mulder (right) studying a rock sample. Credit University of Groningen, Leoni von Ristok Usage Restrictions Credit must be given to the creator. Adaptations must be shared under the same terms. License CC BY-SA Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.