Medical CAT scans like those done in hospitals show a cross-section of a patient’s body with 1-2 mm resolution. But because Lucy isn’t a living patient, much higher-energy X-rays can be used. The computed tomography, or CT, scans done on Lucy reveal internal details on the order of 5-50 microns — less than the width of a human hair. That level of detail could yield unprecedented insight into our ancestors.

Here’s great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-(oh, c’mon she lived 3.2 million years ago)-great-great-great-grandma’s jawbone: