In Memoriam: Tobias "Toby" Owen

Editor's Note: Dr. Tobias "Toby" Owen passed away on March 4, 2017. He was 80.

Tobias "Toby" Owen
Tobias "Toby" Owen (1936-2017)

"It is with deep personal regret and great sadness that I inform you of the death of our friend and colleague, Toby Owen. Each of us not only grieves at the passing of a tremendous individual but also for the loss his family suffers. Toby was the primary inspiration for the MWR experiment on Juno and his work during the proposal and development phases truly enabled the mission to be designed and eventually selected. Toby's pioneering work on the origin and composition of planetary atmospheres and comets was revolutionary and included telescopic, in-situ and laboratory driven models critical to our understanding of elemental abundances and isotopic ratios. Toby played a critical role in many of NASA and ESA's space missions including Viking, Voyager, Galileo, Rosetta, Cassini-Huygens, and of course, Juno. Equally important, Toby also had a rare gift, the ability to explain the space program and how nature works to both the scientist and the public. He will always be with us in spirit."

– Dr. Scott Bolton, Principal Investigator, Juno mission to Jupiter

“We lost a great scientist this week. Toby Owen’s contributions to planetary science will long be remembered, and his love of science will live on through the work of our future missions, as it answers many of his most pressing questions.”

– Dr. James Green, Director, NASA Planetary Science Division

“I am so sad to hear that Toby left us. I met Toby in 1984, one of the fathers of Cassini that became Cassini-Huygens in 1989. He worked tirelessly to help make Cassini-Huygens the great international mission it is today. I have learned so much about the planets and their moons from Toby. A great scientist, a great man, a great explorer. I will deeply miss him. My deepest sympathy to his family and all his friends.”

– Dr. Jean-Pierre Lebreton, Project Scientist for ESA's Huygens probe

The science community lost a giant with the passing of Toby Owen …and I lost a person who literally changed my life. I was one of Toby Owen’s research assistants at Stony Brook University. One spring he let me know about NASA’s Planetary Geology Internship Program. With his recommendation, I became an intern at JPL for the Voyager 1 & 2 Saturn encounters. I can directly trace Toby’s endorsement to my career at JPL, my wife and my children.

God speed Toby,

– Dr. Randii Wessen, A-Team Study Lead Architect, JPL Innovation Foundry

"My strongest memory of Toby was the Galileo “press conference from hell." The Galileo team members were struggling to explain to the press the results from the probe, each telling their story - but with jargon-laden terms that were just not getting across. Eventually, from the audience, Toby stood up and in a few sentences explained the essence of the scientific implications. He not only knew the details of the fundamental planetary science but he also could explain them. He will be sorely missed."

– Dr. Fran Bagenal, Laboratory for Atmospheric and Space Physics, University of Colorado

"Tom Brokaw wrote a book called “The Greatest Generation”, referring to people raised during the Great Depression who then fought in World War II. There was certainly another “Greatest Generation:" that of planetary scientists, those who received their Ph.D.’s between 1960 and roughly 1970, who forged the modern field of planetary science that we know today. Toby is one of the leading lights of that group. Indeed, Toby’s dominant role in forming the DPS is documented here:

This is one of his many pioneering efforts from which we all benefit today. Another is his successful efforts to make Cassini-Huygens a reality and then to ensure that the probe would do great surface as well as atmospheric science. And yet another was in making Juno happen. I join all of us in saying I will truly, truly miss him."

– Dr. Jonathan Lunine, Director Cornell Center for Astrophysics and Planetary Science

"This is heartbreaking news. Toby was one of the most perceptive, thoughtful, and most gracious persons I have ever known. He was incredibly sharp but in a mysteriously soft-spoken way. He could be challenging but never in a way that would make you feel diminished in his presence. Just to talk with him for even a few minutes was to be invited into a realm of awareness where suddenly the world seemed brighter and larger.

"I first met Toby in the mid-1980's during my work with the NASA-ESA Cassini Study Team. He was at Stony Brook in those days ... and once invited me to give a talk out there. I remember being wound way too tight for that occasion ... but Toby so kindly took me home to have dinner afterwards with his wife that evening ... first stopping at the grocery to thoughtfully select the makings of the meal ... then later pouring me a drink in his kitchen.

"After moving to Hawaii, Toby would often have lunch with me on his trips through New York, sometimes at Grand Central Station or in the GISS/Columbia University neighborhood. Although he and I worked in different areas, I nonetheless felt somehow mentored by his encouragement toward the engagement of important questions and the commitment to fighting for important flight experiments.

"Well there is a wonderful (c.1970) photo of young Toby standing with Gerard Kuiper in front of the Texas radio telescope near Marfa, embedded within an article on the history of the DPS posted at

"I am sure that Toby's gentle encouragement of so many people and so much powerfully constructive science will ripple far into the future."

– Dr. Michael Allison, Emeritus Scientist, NASA/Goddard Institute for Space Studies

"Tobias Owen – « Toby » for his friends and colleagues – passed away on March 4, in Sacramento, at the age of 80. He was an exceptional scientist, a pioneer in planetary exploration, and also a man of outstanding charisma.

"Toby’s relationship with Paris Observatory goes back to the early beginning of the 1970s. While he was a professor at Sony Brook University (NY), he played a very active role in the development of the young planetology group at the Observatory. With Daniel Gautier, Catherine de Bergh, Michel Combes and Thérèse Encrenaz, he initiated many research projects around the composition and structure of planetary atmospheres, using space exploration and ground-based observations. He played a major role in the analysis of space data from the Viking mission to Mars and the Voyager missions to the giant planets. With Jean-Pierre Maillard and the French planetology group, he made a series of major discoveries, in particular about the deuterium abundance in the solar system. In a visionary and multidisciplinary approach, he developed numerous research projects on all families of solar system objects, planets, satellites and comets, using all wavelength spectral ranges, from ground and space.

"In the early 1980s, with Daniel Gautier and Wing Ip, Toby became deeply involved in the development of an international space mission, jointly led by the United States and Europe, devoted to the exploration of Saturn and Titan. This project finally became the Cassini-Huygens mission, launched in 1997 and still in operation around Saturn. Beyond its exceptional scientific return, this mission has been an exemplary success in terms of international cooperation between different space agencies.

"In addition to his interest in planetology, Toby early developed interest for the origin of life and the search for extraterrestrial life, a research area that has exploded over the past decades. With Donald Goldsmith and David Morrisson respectively, he published two books on this subject, both now in their third edition. He received many honors and awards, including, in 2009, the prestigious Kuiper Prize of the Division of Planetary Sciences of the American Astronomical Society.

"With his French friends and colleagues, at Paris Observatory and beyond, Toby has developed very strong links of scientific cooperation and friendship. In the early 2000s, he joined the High Scientific Council of Paris Observatory. In 2006, with Daniel Gautier and Jean-Pierre Lebreton, he received the Grand Prix Marcel Dassault of the French Academy of Sciences. In 2007, he became Doctor Honoris Causa of Paris Observatory. Toby was strongly in favor of bringing together scientific communities beyond national frontiers. He made numerous visits in France where he had very close friends, in particular Antonella Barucci and Marcello Fulchignoni. He will be deeply missed by all his friends and colleagues, who will remember his generosity, his availability, his kindness, his simplicity and modesty. All his friends and colleagues, at LESIA and at Paris Observatory, want to express their deepest sympathy to his wife Natasha and his family."

– Th. Encrenaz, C. de Bergh, A. Barucci, M. Fulchignoni, J.-P. Lebreton, Paris Observatory

"Toby was always passionate and kind. I like to remember the discussions we had about Juno and the formation of the solar system (including with his wife Natasha in a small cheese restaurant in Nice!). I will miss him."

– Dr. Tristan Guillot, Observatoire de la Côte d'Azur

Tribute to Toby Owen

"To me Toby was a mentor and a friend. When I knew him on Galileo, in the days of Clayne Yeates, he seemed larger than life. I met him again when I joined Juno. Scott Bolton had asked me to write the History of Juno. Toby, Scott and I often hung out together after science team meetings. He brought a cultural dimension to Juno that I appreciated. We bonded.
He recognized the value of bringing art and literature and music and history and visualization into the realm of Juno. He and Scott even toyed with the idea of a Juno Opera. He was a huge supporter of the Juno Earth encounter, from a philosophical as well as an outreach perspective. He saw the value and supported the building of the models of the Juno trajectory at Earth and at Jupiter. He was an enthusiastic early reviewer, perceptive critic, and ardent supporter of the Juno History as it has evolved. His friendship and support these last 11 years on Juno have been memorable and have enriched my life beyond description. I will surely miss him."

– Theo Clarke, Consultant, Juno Mission to Jupiter

Read More:
*Division of Planetary Sciences of the American Astronomical Society Obituary:

*Juno Mission Team Page:

*The Beginnings of the Division for Planetary Sciences of the American Astronomical Society:

*Dr. Owen's University of Hawaii Institute for Astronomy Page:

Editor's Note: Dr. Tobias "Toby" Owen passed away on March 4, 2017. He was 80.

Tobias "Toby" Owen
Tobias "Toby" Owen (1936-2017)

In Memoriam: Toby Owen

Dr. Tobias C. Owen studied the origin and composition of planetary atmospheres and comets.

An alumnus of the University of Chicago and professor of astronomy at the University of Hawaii, Owen used ground-based telescopes and spectrometers as well as remote sensing and in situ instruments on spacecraft. He was a member of the lander molecular analysis team on NASA's Viking Mission to Mars from 1969 to 1978. He also worked on NASA's Galileo mission to Jupiter, the Cassini-Huygens mission to Saturn and Titan and the Juno mission to Jupiter.

A recipient of the NASA honor medal for exceptional scientific achievement, Owen has conducted published research on a number of topics including atmospheric studies of Venus and comets. He has also participated in international space efforts with Europe and Japan.

Toby Owen Interview, July 19, 2013
by Theo Clarke

The interview was conducted in the magnificent and historic Grand Court, the dining room of the Palace Hotel in San Francisco. The original Palace Hotel was built in 1875 and was destroyed in the great San Francisco earthquake and fire of 1906. The New Palace opened in 1909, occupying the same space as the original. One of the key features of the hotel, old and new, was and is the Grand Court. It originally served as the elegant entrance area for horse-drawn carriages. Since it was rebuilt the Grand Court, also known as the Palm Court, has served as one of San Francisco’s most prestigious dining rooms.

Tobias “Toby” Owen was born in Oshkosh, Wisconsin, one of three brothers. He was raised in Denver, CO and Santa Fe, NM. His parents were intellectuals. They cultivated in the young Owen an interest in literature, music, and the fine arts. He learned to recognize the constellations in the clear, dark skies of Santa Fe, following the planets as they moved through the zodiac. Some thirty years later when he was observing Saturn from the McDonald observatory he noticed that the planet was in the constellation Gemini, where he had seen it while in Santa Fe. In one Saturnian year, he had grown from a boy staring at the night sky to an astronomer recording the spectra of planets and their satellites. After his 5th grade the Owen family moved to Milwaukee, WI. As a youth Owen’s passions included sailing, tennis, swimming and fly-fishing. He competed successfully in tennis and swimming at the high school level. He played football in the 7th grade, but unfortunately broke his back during a game. He was stuck in a cast and brace for a year. While practically immobilized he built a 6-inch telescope, grinding the mirror in his basement. He observed Jupiter and the other planets, seeing those moving points of light in the night sky revealed as worlds that could be explored.

He was awarded an academic scholarship to the University of Chicago and entered the University at the age of 15. He likes to say that next to a fine education, the most valuable experience he had at the University was learning to play respectable tennis from the excellent coach in the fine field house. What a surprise that was! Another surprise was the presence of a 6-inch refracting telescope on the roof of the physics building. With a high-quality lens and a clock drive, this instrument provided welcome opportunities for a young student eager to carry on the programs begun with his home-made telescope in Milwaukee.

Owen took a year off after his BA to study as an exchange student at the Goethe Universitaet in Frankfurt, Germany. While becoming fluent in German, he traveled through Greece and the west coast of Turkey, fulfilling fantasies kindled by reading Homer and the Greek myths while growing up.

Owen earned his BS and MS in Physics at the U of Chicago, and went on to earn his PhD in Astronomy in 1965 at the U of Arizona. He was a student of the late Gerard P. Kuiper, an illustrious Dutch-American astronomer who was probably the leading planetary scientist in the world at that time. Kuiper started the Lunar and Planetary Laboratory (LPL) at the U of Arizona in 1960; Owen was one of the first students. He found Kuiper to be an inspiring scientist and a stimulating thesis advisor.

In 1968 Owen and Carl Sagan, along with a parallel effort by Joseph Chamberlain, founded the Division of Planetary Science (DPS) as a subdivision of the American Astronomical Society (AAS). In 1984 the DPS established the Gerard P. Kuiper prize, to be awarded annually to recognize and honor those scientists whose achievements have most advanced our understanding of planetary science. Owen was awarded the Kuiper prize in 2009.

After earning his PhD, Owen served as Professor of Astronomy for 20 years at the State University of New York (SUNY), Stony Brook, making observations of Jupiter and the other planets with the large telescopes in Texas, Arizona, and California. He joined the NASA Viking mission to Mars in 1971. His goal was to discover and study the noble gases in the Martian atmosphere to tease out some of the secrets about the origins of atmospheres of both Mars and Earth. Viking’s mass spectrometer (under the leadership of Klaus Biemann) showed that Argon, Krypton and xenon in the atmosphere of Mars have the same relative abundances as they do on Earth; distinctly different from the gases found in ordinary meteorites.. Owen suggested that this unique similarity implied a common carrier as a source of noble gases and hence some fraction of other volatiles like nitrogen and carbon dioxide in both Mars and Earth. If so, it would offer strong evidence that Mars was once a habitable planet like Earth.

Owen and Akiva Bar-Nun proposed that the common carriers of volatiles to both planets could have been comets. Bar-nun’s laboratory experiments had shown that ice forming at low temperatures can trap the noble gases in the observed abundances. The comet delivery hypothesis will be rigorously tested when the Rosetta spacecraft reaches its target, Comet 67P/Churyumov-Gerasimenko, in 2015. Owen is a member of the mass spectrometer team.

Owen joined the Voyager Mission to the outer solar system as a member of the Imaging Team led by Brad Smith. He remained a team member for all 4 Voyager outer planet encounters. Owen proposed and led a successful search for a Jovian Ring with the Voyager cameras. As chair of the IAU outer solar system nomenclature committee, Owen established rules for naming features on satellites and names for newly discovered moons. He proposed many of these names himself. Overall, more than 2000 new names were applied by the full complement of IAU Nomenclature Committees.
Owen left Stony Brook in 1989 for a position as Astronomer and Professor at the Institute for Astronomy of the University of Arizona. He joined the Galileo Mission to Jupiter as an interdisciplinary scientist and a member of Hasso Nieman’s mass spectrometer team on the atmospheric probe. All of the heavy elements the probe could measure were found to be enriched by about a factor of three compared with solar abundances. Owen stressed that this discovery meant that the classical paradigm for the formation of the outer planets had to be shifted. However, it proved to be impossible to measure the abundance of oxygen. Because this is the third most abundant element in the universe, its abundance must be known to understand Jupiter’s origin and present interior structure. Furthermore, oxygen is the essential ingredient of water, the sine qua non for all the living matter we know. Hence the history of water in our solar system is intimately connected with the origin and evolution of life.

On Jupiter, oxygen must be present in the form of H2O, just as we find CH4 and NH3, not C and N. Thus to measure the global abundance of oxygen, we must reach below the level where H2O condenses. Unfortunately the Galileo probe measurements were stopped well above this level owing to the extreme heat and pressure. A measurement of the oxygen abundance is one of the key objectives of the Juno mission.

As the 1980’s began there was intense competition for the next NASA “flagship” mission. Owen was chair of a NASA Outer Solar System working group that proposed a Saturn Orbiter with a Titan probe. Simultaneously, Owen’s friend and colleague Daniel Gautier with Wing Ip had assembled a group of scientists in Europe who approached ESA with the same idea. It rapidly became clear that neither side could afford such a mission; collaboration seemed a logical solution. The Americans would take responsibility for the orbiter, to be named Cassini (as suggested by Ip) and the Europeans would make the probe, named Huygens. Two international working groups were established to develop a proposal for the Huygens component. Owen was chair of the US group, Gautier and Ip led the European team. Together they hammered out the Cassini/Huygens proposal which was ultimately approved by ESA and NASA in 1989. Owen fought hard for this mission, making winning presentations to the ESA solar system division and the NASA administrator, and lobbying the US Congress for funding. Cassini/ Huygens has been outrageously successful, soft-landing the Huygens probe for a series of experiments on the surface of Titan in 2005 while the Cassini orbiter is still obtaining data while circling Saturn as this is being written. Owen is an interdisciplinary scientist and a member of Hasso Niemann’s mass spectrometer team.

{Both Giovanni Domenico Cassini and Christian Huygens were keen observers of the Saturn system. Here is Huygens, putting discovery of Titan (‘the brightest’) in context: “The Jovial (sic) [satellites] we owe to Galileo, ‘tis well known: and anyone may imagine he was in no small rapture at the discovery. The outermost but one, and brightest of Saturn’s, it chanc’d to be my lot to have first sight of it in the year 1655. The rest (4 at the time) we may thank the industrious Cassini for…”}

Owen related how he met Scott Bolton. Owen was having lunch in the JPL cafeteria just after a Galileo mission meeting, and Bolton came over and asked him what one could do with a spacecraft going under the radiation belts at Jupiter. Owen answered with one word, “Water!” Bolton subsequently added several other important objectives that could be satisfied by a polar orbiter inside the radiation belts. This became a proposal that Bolton and Owen organized with the help of the instrument team leaders for a new mission to Jupiter, appropriately named “Juno.” Just as Juno the goddess, with her special powers, penetrated the clouds Jupiter had cast over the Peloponnese to conceal his dalliance with the nymph Io, so Juno the spacecraft, with its special powers, will penetrate the clouds of Jupiter to reveal the secrets the planet conceals.
Bolton named Owen Chair of the Juno Origins Working Group. Among the expected results from the mission, Owen is particularly interested in the abundance of water in Jupiter’s atmosphere and its bearing on the enrichment of heavy elements, the planet’s origin and its effects on the distribution of matter in the solar system. Constraints on the mass and size of a core, if one exists are also of critical importance.

In 2011 Owen retired from the U of Hawaii and moved to Sacramento, CA with his wife Natasha. He maintains an Emeritus and Research Affiliate position with the University of Arizona Institute for Astronomy and remains an interdisciplinary scientist on Cassini and a participant in the Curiosity and Rosetta Missions as well as CoI and Acting Chair of the Origins Working Group on Juno.