Earth & Space
Jonathan Fortney, Dan Costa honored by American Geophysical Union
Astronomy and astrophysics professor Jonathan Fortney receives 2026 Whipple Award and ecology and evolutionary biology professor Dan Costa named 2026 AGU Union Fellow
Professors Jonathan Fortney and Dan Costa
The American Geophysical Union (AGU) announced on September 23 that Professors Jonathan Fortney and Dan Costa have been selected for major honors in AGU’s 2026 recognition program. Fortney will receive the 2026 Whipple Award for contributions to the field of planetary science, and Costa was named an AGU Union Fellow in recognition of his groundbreaking contributions to marine ecology, animal physiological ecology, and ocean conservation.
AGU, the world’s largest Earth and space science association, annually celebrates scientists who have transformed our understanding of the universe, impacted communities, and advanced solutions for a sustainable future. Both honorees join an elite group of international leaders recognized by AGU for advancing scientific discovery.
Jonathan Fortney
Fortney is a leading international authority on the atmospheres and interior compositions of planets in our solar system and exoplanets orbiting distant stars. His research focuses on developing pioneering theoretical models of planetary physics and chemistry.
Over his career, Fortney served on the science team for NASA’s Cassini Mission, which revolutionized our understanding of Saturn, as well as NASA’s Kepler Mission, which discovered more than 3,000 exoplanets. His ongoing research includes demystifying sub-Neptune “steam worlds” and analyzing data on exoplanet atmospheres from the James Webb Space Telescope. Fortney also directs UC Santa Cruz’s Other Worlds Laboratory, which builds and fosters new collaborations in exoplanet science.
Highlighting his broad scientific influence, Clarivate named Fortney to its annual Highly Cited Researchers list. Fortney achieved this distinction because his published research papers rank in the top 1% by citations for his field and publication year globally. His consistent recognition on the list reflects his substantial impact across planetary science and helped position UC Santa Cruz as the No. 1 public university in the nation for highly cited researchers in 2025.
Dan Costa
Formerly the director of UC Santa Cruz’s Institute of Marine Sciences, Costa’s election as a Union Fellow is one of the highest honors conferred in Earth and space sciences. Bestowed annually on a tiny fraction of AGU’s total global membership since 1962, fellowship is reserved for members who have achieved major scientific breakthroughs, paradigm shifts, or sustained transformative impact as vetted by peer committees. Fellows serve as scientific authorities invited to advise government agencies, educational institutions, and international organizations outside Earth and space science, while motivating scientific excellence and representing AGU’s highest standards of research integrity.
Costa was selected for his pioneering work in the ecophysiology, diving behavior, and foraging ecology of marine mammals and seabirds. An innovator in biotelemetry and electronic animal tagging (biologging), Costa helped transform oceanographic observation by equipping marine animals with miniature instruments that record migration paths, diving depths, and ocean conditions.
Co-founder of major international research initiatives such as Tagging of Pacific Predators (TOPP), Costa’s decades of field research at California’s Año Nuevo State Reserve and in Antarctica, have advanced our understanding of elephant seals, sea lions, and marine ecosystems under environmental change.
Fortney and Costa will be formally recognized during an honors ceremony at AGU’s 2026 annual meeting in December.