Experiment on La Palma (IMAGE) Johannes Gutenberg Universitaet Mainz Caption The experiment on La Palma: The laser beam (yellow) generates an artificial guide star in the mesosphere. This light is collected in the receiver telescope (front left). The laser source and the receiver telescope are eight meters away from each other. Credit photo/©: Felipe Pedreros Bustos Usage Restrictions This image may only be used in connection with the press release "Earth's magnetic field measured using artificial stars at 90 kilometers altitude", issued by Johannes Gutenberg University Mainz on November 14, 2018. License Licensed content 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.