Manganese Nodules (IMAGE) California Institute of Technology Caption Manganese oxide nodules generated by the bacteria discovered by the Caltech team. The nodules are generally about 0.1 to 0.5 millimeters in diameter. Images are scanning electron micrographs with false colorization. Credit Hang Yu/Caltech Usage Restrictions Please use credit 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.