Astronomers Utilize Chemical Archaeology to Uncover the Evolutionary History of Distant Galaxies

Astronomers have successfully decoded the chemical composition of the spiral galaxy NGC 1365, marking the first time a technique known as "extragalactic archaeology" has been applied with such precision outside the Milky Way. Published in the journal Nature Astronomy on March 23, 2026, the study involved researchers from the Harvard-Smithsonian Center for Astrophysics who analyzed spectroscopic data to trace the galaxy's development over billions of years. By mapping the distribution of elements like oxygen, nitrogen, and sulfur, the team gained unprecedented insight into the complex processes of star formation, gas movement, and galactic mergers that shaped the structure of the galaxy.

The research relies on data collected by the Irénée du Pont Telescope during the Carnegie TYPHOON survey, which provided high-resolution, three-dimensional maps of the galaxy’s chemical makeup. Scientists compared these observations against extensive computer simulations, such as the Illustris Project, to identify patterns that reveal the galaxy's past. Lead author Lisa Kewley emphasizes that this method functions similarly to terrestrial archaeology, where present-day evidence serves as a record of historical events. This breakthrough provides a new framework for understanding how galaxies evolve and offers significant clues regarding the origins of our own Milky Way.