NOAA handout image shows the Sun’s activity on March 8, 2012. A strong geomagnetic storm is racing from the Sun toward Earth, and its expected arrival on Thursday could affect power grids, airplane routes and space-based satellite navigation systems, U.S. space weather experts said. REUTERS/National Oceanic and Atmospheric Administration/Handout (UNITED STATES – Tags: ENVIRONMENT SCIENCE TECHNOLOGY) FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. IT IS DISTRIBUTED, EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS