Guide Star for Biomedical Imaging (IMAGE) Washington University in St. Louis Caption A WUSTL scientist has invented the biomedical equivalent of the astronomers' guide star.To correct for atmospheric blurring, astronomers sometimes shine a laser into the sky near the spot where a telescope is pointing. The laser beam energizes sodium atoms naturally present above the stratosphere, producing a glowing artificial star called a guide star. The astronomers use the ‘twinkling’ of this guide star to continuously compensate for the effects of atmospheric turbulence on the light they are collecting from nearby stars. The guide star thus allows astronomers to obtain much sharper, more detailed images free of atmospheric blurring. Shown here is a laser beam projected into the night sky from the Keck-2 telescope on Mauna Kea, Hawaii. Credit Paul Hirst/Creative Commons 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.