Mary K. Hudson

Dartmouth College

2017 John Adam Fleming Medal Winner

Mary K. Hudson was awarded the 2017 John Adam Fleming Medal at the AGU Fall Meeting Honors Ceremony, held on 13 December 2017 in New Orleans, La. The medal is for “original research and technical leadership in geomagnetism, atmospheric electricity, aeronomy, space physics, and/or related sciences.”


Mary K. Hudson, AGU Macelwane medalist and Fellow, is, without peer, a leading international expert in theoretical studies and understanding of Earth’s radiation belts and space plasma environment. Mary Hudson’s research productivity and versatility in a wide range of space plasma topics and her outstanding service to the space physics research community amply qualify her to be the 2017 AGU Fleming medalist.

Early in her career Mary made significant contributions to theoretical studies of plasma processes and instabilities in Earth’s ionosphere. These included a novel tackling of the spread F problem, the existence of which produces (among other deleterious effects) scintillations and outages in communication satellite signals.

The existence of signals in the ­ultralow-​­frequency band in Earth’s magnetosphere has been investigated almost since the advent of sensitive magnetic ­field–​­measuring instruments in the 19th century. Mary recognized early the importance of these waves for affecting radiation belt dynamics and effectively created a new area of radiation belt research. Seminal theoretical and computer modeling work by Mary (including guidance of her students and colleagues) elucidated the fundamental importance of these waves for the transport and energization of trapped particle radiation.

As ­co–​­principal investigator (­co-PI) for two of the
five instruments on each of the dual Van Allen Probes
(VA Probes) spacecraft and as ­co-PI for the NASA Balloon Array for ­Radiation-​­belt Relativistic Electron Losses (­BARREL) studies of precipitating electrons, she has provided the essential underlying theoretical and modeling expertise to these projects, as well as to the entire VA Probes program. Her leadership participation has been essential for interpretation and major advances in understanding.

Mary has unselfishly served the space research communities in numerous significant capacities. These include as ­co-PI for the ­decade-​­long National Science Foundation (NSF) Science and Technology Center CISM (Center for Integrated Space Weather Modeling). She served as chair of the NSF Geospace Environment Modeling (GEM) Steering Committee. Mary served exceptionally well as cochair of the National Academies of Sciences, Engineering, and Medicine Committee on Solar and Space Physics. In the AGU family, Mary served on the Education Committee of the Space Physics and Aeronomy section and as secretary of the section. Very importantly, in her professional career at Aerospace and in her several academic positions (including a tenured endowed position at Dartmouth) she has served unselfishly (and often unheralded) as a strong mentor and a talented role model for women physicists and women in technical responsibilities.

—Louis J. Lanzerotti, New Jersey Institute of Technology, Newark; also at ­Alcatel-​­Lucent Bell Laboratories, Murray Hill, N.J.


It is my great honor to receive this award around the 60th anniversary of the launch of the first “artificial satellites,” as they were called, Sputnik 1 on 4 October 1957 and Explorer 1 on 31 January 1958, first reporting the Van Allen radiation belts. I have had the privilege of studying these in recent years using remarkable data from the NASA Van Allen Probes. I began two solar cycles prior when the Sun changed our view of static radiation belts and space weather emerged as a growing concern in a world now connected by artificial satellites.

I became interested in space and the cosmos early because of the space race and my childhood telescope. I was fortunate to attend a great public university, the University of California, Los Angeles, and had the opportunity to work with pioneers in radiation belt studies at the Aerospace Corporation, George Paulikas and Bern Blake, and another radiation belt pioneer, Charlie Kennel, my thesis supervisor.

Arriving at the University of California, Berkeley in 1974, I was again fortunate when Forrest Mozer led the first electric field ­double-​­probe experiment to study processes that produce the aurora. A group of us including Bill Lotko, Bob Lysak, Ilan Roth, Cindy Cattell, John Wygant, and Mike Temerin—all barely 30—made a reputation for ourselves helping to explain the exciting ­S3-​­3 satellite observations

I might have stayed in the “auroral zone” had the opportunity not arisen for faculty positions at Dartmouth. My husband, Bill Lotko, and I are both greatly indebted to Professor Bengt Sonnerup, who encouraged a California native to make the leap to rural New Hampshire. I am grateful to numerous very talented students, postdocs, and senior colleagues who made the leap to the Granite State, as well as my funding agencies. It is a great pleasure to share this moment with many of you tonight. James Van Allen told me when he handed me the Macelwane award in 1984 that I was the first woman to receive it. I am most happy this is not the case for the Fleming—Janet! Grandma Sadie Martin “leaned in” a long time ago as one of only four women in her graduating class. Our two wonderful daughters, Lauren and Anna, are paving the way for granddaughters Sally and Maddie to aspire to anything they want to be. I thank them for the future and my husband, Bill Lotko, who has never wavered in his encouragement.

—Mary K. Hudson, Dartmouth College, Hanover, N.H.