Micrometeorites (IMAGE) University of Washington Caption These tiny meteorites, about half a millimeter across, fell into the ocean and were collected from the deep sea. Like the samples used in the new study, these more recent micrometeorites are made of iron. Credit Donald Brownlee/University of Washington Usage Restrictions With 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.