Satellite Image (IMAGE) University of Granada Caption Satellite image showing the two most frequent meteorological scenarios where huge amounts of viruses (transported by Atlantic Ocean depressions) and bacteria (transported by Saharan dust intrusions) are deposited in the high mountains of Sierra Nevada and at a global scale. Credit NASA Visible Earth. 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.