MESSENGER Spacecraft (IMAGE) University of Arizona Caption The MESSENGER spacecraft will orbit Mercury in an effort to study the geologic history, the enigmatic magnetic field, the surface composition and other mysteries of the planet. The shield visible on the probe's right side protects its sensitive instruments from the sun's intense heat. Credit NASA/JHUAPL/CIW Usage Restrictions Usage only permitted in conjunction with reporting/posting of this news release. Image credit must be included. 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.