Natural Sciences

(Top, from left) Cherie Kagan, Daniel Krashen, and George Pappas. (Bottom, from left) Kai Tan and Patrick Walsh.

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To visualize the nanoscale structures, the Tertuliano lab often uses large-scale models like the one pictured.

(Image: Sylvia Zhang)

The Dark Energy Survey used a 570-megapixel camera mounted on the 4-metre Victor M. Blanco Telescope in Chile to image 5,000 square degrees of southern sky. The survey discovered more than 1,000 supernovae and mapped millions of galaxies to help astronomers better understand the accelerating expansion of our universe.

(Image: Courtesy of Dark Energy Survey Collaborative)

Image: Sciepro/Science Photo Library via Getty Images

2025 graduate Srishti Jainapur recording the temperature on a freezer.

(Image: Courtesy of Penn Climate)

High-speed laboratory images capture two distinct “sandball” shapes formed when raindrops strike dry, sloped sand and roll downhill. (Top) Peanut-shaped sandballs, where grains coat the surface of a liquid core. (Bottom) Donut-shaped sandballs, which densify into rigid, wheel-like structures with a hollow center, enabling far more efficient sediment transport than splash erosion alone.

(Image: Daisuke Noto)

Image: Dowprasook Deenu via Getty Images

Despite the commonality of water and ice, says Penn physicist Robert Carpick, their physical properties are remarkably unique.

(Image: mustafahacalaki via Getty Images)