UNIVERSITY PARK, Pa. -- When Erin DiMaggio was an undergraduate student, she had a summer internship with the Smithsonian National Museum of Natural History. Little did the 19-year-old know then that one day she would help develop a permanent exhibit for the museum.

DiMaggio, now an assistant research professor of geosciences in Penn State’s College of Earth and Mineral Sciences, has an exhibit featured in the museum’s “The David H. Koch Hall of Fossils - Deep Time,” which reopened this summer.

Closed in 2014 for remodeling, the new, immersive 31,000-square-foot dinosaur and fossil hall explores the story of Earth’s deep past and tracks the history of life on this planet.

Visitors to the “How Do We Date Fossils?” exhibit are greeted by a large headshot of DiMaggio smiling and photos of field work in Africa. Informative panels teach visitors about the primary methods of dating; relative dating — a method that uses the position of fossils within rock layers to determine their age — and absolute dating — the method that uses radioactive minerals in rocks as geological clocks.

“This exhibit addresses how we look for clues in the surrounding rocks to determine the ages of fossils,” said DiMaggio. “The display explains both relative and absolute dating methods. For example, the decay of potassium-40 to argon-40 is an absolute dating method we often use to date rocks in Africa that contain fossils of early humans.”

After learning about dating, visitors can test their knowledge with the “Fossil Dating Game,” where opening drawers in simulated “rock layers” can provide clues for aging a fossil.

To DiMaggio, having an exhibit in the reopened hall was a rewarding return to the Smithsonian.

“My internship at the Natural Museum of Natural History jump-started my career in research. Working with high-level researchers at such a young age gave me the confidence needed to pursue a career in geosciences,” DiMaggio said. “It is quite a rewarding experience to return and see your face and research featured in one of the exhibits.”

DiMaggio earned three degrees, all in geological sciences: a bachelor of science from the University of Michigan in 2004, and a master of science in 2007 and doctorate in 2013 from Arizona State University.

Her research focuses on two- to six-million-year-old sedimentary rocks and volcanic ash layers in Ethiopia and Kenya. The sedimentary rocks she studies contain fossils of vertebrate fauna, including those of early humans, making these areas important places for studying human evolution.

The National Museum of Natural History is one of the most visited natural history museums in the world. Opened in 1910, the museum is dedicated to maintaining and preserving the world’s most extensive collection of natural history specimens and human artifacts. For more information about the David H. Koch Hall of Fossils - Deep Time, visit https://naturalhistory.si.edu/exhibits/david-h-koch-hall-fossils-deep-time online.