
The Whipple Award, the highest honor given by the American Geophysical Union Planetary Sciences section, is named for Fred Whipple, a famed space scientist most noted for his work on comets.
This year, we have selected Alfred McEwen, professor at the Lunar and Planetary Laboratory, University of Arizona, as the 2015 Whipple Award winner. Before, during, and after his Ph.D. at Arizona State University, Dr. McEwen worked at the U.S. Geological Survey branch of astrogeology in Flagstaff, moving to the University of Arizona in 1996.
Dr. McEwen is interested in how planets evolve. His mission involvement began in 1989 as a guest investigator with the Voyager imaging team for Neptune encounter. Since then, he has been involved with Galileo, Cassini, Clementine, the Mars Global Surveyor, Mars Odyssey, the Mars Reconnaissance Orbiter (MRO), the Lunar Reconnaissance Orbiter, and the ExoMars Trace Gas Orbiter, as well as current proposals for future missions. He is deputy principal investigator (PI) of the new Europa Imaging System.
Perhaps his first revolutionary work was the discovery of especially high temperature volcanism on Io. He has published ~200 papers with a who’s who of planetary scientists as collaborators. He has served as an indispensable reminder that better mission data produce better understanding of planets and provide the surprises that we don’t anticipate.
Alfred is the principal investigator of the incredibly successful High-Resolution Imaging Science Experiment (HiRISE) on MRO. Along with critical data about the planet’s past, HiRISE has provided conclusive evidence that Mars remains a dynamic planet. Dr. McEwen’s most important contribution to our field may be the linear features that darken and lengthen during the warmest periods, only to fade away as surface temperatures drop—these recurring slope lineae are most probably seasonal flows of brine on Mars today.
That inquisitive nature, the openness to new ideas and people, and—most of all—his ability to produce results have marked his career and are worthy of the Whipple Award. Many congratulations to Alfred S. McEwen for outstanding contributions to planetary science.
—Linda T. Elkins-Tanton, Arizona State University, Tempe

Water ice in the Martian mid‐latitudes has advanced and retreated in response to variations in the planet's orbit, obliquity, and climate. A ...


