Sphere Photo (image) Northern Arizona University Caption A colorized scanning electron microscope image of a glassy carbon sphere that contains evidence of extraterrestrial impact. The sphere measures about .012 inches in width. Credit SEM imaging by Jim Wittke Usage Restrictions Must include photo credit 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.