Quantum Signals from Space (IMAGE) Optica Caption From the ground, researchers measured laser signals that originated from a satellite and traveled through Earth's gravitational potential and the turbulent atmosphere. The successful characterization of quantum features under such conditions is a precondition for the implementation of a global quantum communication network using satellites that would link metropolitan area quantum networks on the ground. Credit Picture of the Earth: Google, picture of the satellite: ESA Usage Restrictions None 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.