Women in Planetary Science: Meet Fran Bagenal
Fran Bagenal is professor of astrophysical and planetary sciences at the University of Colorado, Boulder and is a co-investigator on the New Horizons mission. Her main area of expertise is the study of charged particles trapped in planetary magnetic fields.
This is the intro paragraph from Comparative Planetary Environments, F. Bagenal, in Heliophysics: Plasma Physics of the Local Cosmos, C.J. Schrijver, G.L. Siscoe (eds), Cambridge University Press, pp 360-398, 2009.
The nature of the interaction between a planetary object and the surrounding plasma depends on the properties of both the object and the plasma flow in which it is embedded. A planet with a significant internal magnetic field forms a magnetosphere that extends the planet’s influence beyond its surface or cloud tops. A planetary object without a significant internal dynamo can interact with any surrounding plasma via currents induced in an electrically conducting ionosphere. All the solar system planets are embedded in the wind that streams radially away from the Sun. The flow speed of the solar wind exceeds the speed of the fastest wave mode that can propagate in the interplanetary plasma. The interaction of the supersonic solar wind with a planetary magnetic field (either generated by an internal dynamo or induced externally) produces a bow shock upstream of the planet. Objects such as the Earth’s Moon that have no appreciable atmosphere and a low-conductivity surface have minimal electrodynamic interaction with the surrounding plasma and just absorb the impinging solar wind with no upstream shock. Interactions between planetary satellites and magnetospheric plasmas are as varied as the moons themselves: Ganymede’s significant dynamo produces a mini-magnetosphere within the giant magnetosphere of Jupiter; the electrodynamic interactions of magnetospheric plasma flowing past the atmospheres of volcanically active Io (Jupiter) and Enceladus (Saturn) generate substantial currents and supply more plasma to the system; moons without significant atmospheres (e.g. Callisto at Jupiter) absorb the impinging plasma. The flow within magnetospheres tends to be subsonic, so that none of these varied interactions forms a shock upstream of the moon.
1. What first inspired you to study space science?
I was an Apollo kid. As a teenager in rural England I stayed up through the middle of the night to watch the Apollo astronauts walk on the Moon. Every week I watched the BBC “Horizons” documentaries that showed the current scientific ideas – I was most interested in plate tectonics and space exploration. My elder brother was studying at nearby Cambridge University and invited me to a talk that was being given by Carl Sagan. He talked about Mariner 9 exploration of Mars, showed the images (fuzzy compared with recent), and what impressed me was the way he addressed the questioning from the (rather stuffy) Cambridge academics with honest discussion of the science and intellectual challenges. I studied physics/geophysics at Lancaster University, thinking about a career as an exploration geophysicist but keeping an eye on the US space program. I did not know what to do for graduate studies so I put off the decision by applying to spend a year studying in the US. I ended up at MIT and took a summer job working with the Voyager Plasma Science team, just as the two Voyagers were launched. So, the choice was obvious to stay and work on data from Voyager at Jupiter. I wrote a thesis on the exciting new data obtained when Voyager flew through the Io plasma torus – presenting my first AGU presentation at a Voyager special session chaired by Carl Sagan.
2. Where did you postdoc, and for how long?
Amusingly, I got my first job offer via a conversation in a woman’s room. At the 1981 Magnetospheres of the Outer Planets meeting my thesis work was being shown by several speakers and during a break a senior woman scientist asked me what I planned to do next. I said I was thinking of going back to England. She went back to the meeting and at the next break a British scientist she was sitting next to offered me a job. After a year finishing up work at MIT (and a trip to climb mountains in Peru) I started a post-doc at Imperial College in London. I spent 5 years at IC – getting a fellowship to support later years. This was at the height of Margaret Thatcher’s slashing of funds for academic research – things did not look too good for staying in Britain. And there was very little planetary research in the UK.
3. How did you choose your current institution?
It became clear to me that I wanted to return to the US – mostly for the opportunities for space research but also because I realized I felt more comfortable in the american academic system. I was on vacation in Boulder (visiting a British climber who was living there – now my husband of 20 years) and, while I was in town, gave a talk at NCAR. I was urged to apply to their visiting scientist program. Just as I was wrapping up things in London to start my NCAR visiting position, I got an email from Voyager colleagues in Boulder saying that the University of Colorado was looking for faculty, particularly underrepresented minorities, in the physical sciences. Faculty positions are rare – and while some might question taking such a position – I realized that it was an opportunity and it would be up to me to do the best with it. And, besides, as a climber and skier, Boulder was clearly the place I wanted to live. I was given tenure 4 years later and have been on the faculty at CU for 21 years.
4. Do you have any advice for students and postdocs just starting their career in space science?
It’s a great job! And there are all sorts of jobs – mission design, mission operations, data analysis, modeling. You need to think about what you like doing most – is it digging through the data to find the nugget you know is there? Is it developing a model and seeing the science evolving in progressively complex plots? Is it discussing with a team how to implement a set of measurements? Yes, grades are important. Yes, publications are important. But also, contrary to common misconception, getting on with people is also important – perhaps as important as solving big equations. Talk with a range of people about what it takes to succeed in different types of jobs.
5. Have you been involved in missions? What are some of the challenges and rewards?
Yes – the best part of my job – Voyager, Galileo, Deep Space 1, New Horizons and Juno – usually on the science team as a plasma scientist. The rewards are, without question, are seeing the new data coming in. The challenges are the long stages it takes to get there – advocating the mission, proposing, designing, building, launching, getting out to the planet – and then, finally, the data come in. For Jupiter missions the process takes about 10-15 years. We started working on a mission to Pluto in 1989 – 26 years before New Horizons is due to fly past Pluto.
6. Have your students been involved as well?
Of course. Graduate students are directly involved in analyzing or modeling mission data. It is harder for undergraduates to be involved because they usually do not have sufficient programming experience. But we now have programming courses and I have begun employing undergraduates.
7. Do you have a favorite class you like to teach and why?
Hummmm….. I have just started a sabbatical so I am feeling a bit burnt out on teaching. But I expect I will bounce back by next fall. The best classes are the smaller classes for majors in planetary science – when students keep asking great questions and we discuss the latest data coming in from a planetary mission.
Thanks for these great answers Fran!