One year ago, the European Space Agency’s (ESA) Huygens probe finally landed on Titan, Saturn’s moon, after a 7-year journey aboard NASA’s Cassini spacecraft. On 14 January 2005, planetary scientists, astrobiologists, and engineers gathered at the Cité des Sciences in Paris for an event hosted by ESA and the Centre National d´Etudes Spatiales (CNES) to observe the reception of the first signals broadcast by the probe. Eric Hébrard, who was in the second year of his Ph.D. at the Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA) in Créteil, was among the researchers waiting to hear whether the Huygens mission had succeeded. "We had to wait for 4 to 5 hours before getting a signal. It was pretty stressful," says Hébrard. But "when we saw the first picture of the surface, it was really rewarding, especially for my boss"--François Raulin--"who had worked longer on this project."
Although Hébrard was fairly new to the Titan team, the moment was the culmination of years of dreaming and hard work for him, too. He had been observing stars, wondering about the origins of life, and steering his career in this direction since childhood.
A Child of the Stars
"I already had an interest in astronomy in high school," recalls Hébrard. At 13, he joined a nonprofessional astronomical association in his neighbourhood in Paris, called Les Enfants des Etoiles. "We looked at the stars, and we had very nice telescopes; it was cool. We talked about theoretical stuff to explain the planets and the stars and the formation of the universe." It quickly became clear to him that he wanted to be immersed in this field, and his fondness for science fiction books only added to his passion for space.
After obtaining his baccalauréat (equivalent to A levels in the UK) in 1997, Hébrard followed a 2-year intensive course in mathematics, physics, and chemistry at the Lycée Saint-Louis in Paris in preparation for the competitive entry to the French engineering grandes écoles. Such courses give a general background rather than a specialisation, but Hébrard was able to spend some time working on astrobiology for a report he had to write. At the end of his second year, Hébrard decided that he didn't really like engineering and chose to do another preparatory year; at the end of his third year, he ranked high enough to join the Ecole Normale Supérieure (ENS) in Paris, a grande école dedicated to research and teaching.
In his first year at ENS, he completed the equivalent of a combined Bachelor’s and Master’s degree in chemistry. "[Then] I had the opportunity to do a 1-year internship abroad," he says. So he looked at both the NASA Astrobiology Institute (NAI) and the National Research Council (NRC) Web sites for places in the United States where he could gain some research experience in the field that had always interested him, astrobiology. "I found some very high-level labs, and I just asked if they were willing to accept me as a scholar for a year," he says. Professor James Ferris’s lab at the NASA Specialized Center of Research and Training (NSCORT) at the New YorkCenter for Studies of the Origins of Life was one of the first that agreed to take him on. Hébrard says he was surprised to get many positive responses and so quickly. "I had underlined my affiliation to the ENS. Some people knew the ENS and contacted my supervisor." His keenness to work in astrobiology may also have helped convince the labs’ directors, he thinks.
In Ferris's lab, Hébrard conducted research on the formation of RNA oligomers--potential precursors of life--on clay minerals believed to be present on the primitive Earth. It was Hébrard´s first real taste of research, and the experience confirmed his idea that astrobiology was the right field for him. During that year, Hébrard also presented a poster at an international conference in Mexico on the origins of life, organised by the International Society for the Study of the Origin of Life (ISSOL). He recalls the meeting as a special event as he met many scientists he admired. "It was very motivating," he says.
Going for Titan
When he returned from the United States in 2002, Hébrard did a D.E.A. ( diplome d´études approfondies), a prerequisite to a Ph.D. in France, studying Titan´s atmosphere as part of the Groupe de Physico-Chimie Organique Spatiale (GPCOS) at LISA, whose principal investigator François Raulin is involved in the Huygens mission. Hébrard had secured this D.E.A. position before leaving France a year before. He eventually obtained his D.E.A. in 2003, and he decided to continue his work on Titan in the same lab as a Ph.D. student.
For astronomers--especially astrobiologists--Titan is closer to Earth than the physical distance would first suggest. It is the only moon in the solar system to have a dense atmosphere that resembles the early terrestrial atmosphere. The photochemical processes taking place in Titan’s atmosphere, astrobiologists believe, may provide clues of how organic molecules--and eventually living things--were generated on the primitive earth. While working on his D.E.A.--and now his Ph.D.--Hébrard has been involved in modelling these processes. His role, specifically, is to determine how uncertainties in the data could affect the simulation of the photochemical processes occurring in Titan's atmosphere.
Hébrard’s research is not directly linked to the Huygens mission. "I would have been able to run my models even without the success the mission has known," he says. But the year's worth of data that has arrived from Titan has allowed him to check his studies against new observational data and to improve his assessment of the impact of data uncertainties. The success of the mission also had another positive effect on Hébrard’s Ph.D. "I suppose nothing really dreadful would have happened to my Ph.D. if the mission had failed, but excitement would have probably been killed in the whole community and this would have affected [my excitement] for a large part." If that had happened, decades would probably have passed before any new mission was launched to Titan, and "my immediate future with Titan as a field of research would have seemed condemned."
Due to the expense and the long time frame of much astronomical research, astronomers face a great deal of professional risk, in both research and career terms. But, says Hébrard, the rewards are well worth it. "It was especially exciting to work on this project," he says, because it enabled him to see a place that people knew very little about and gave him a greater sense of being one of the pioneers. Hébrard also enjoys the media attention that space missions traditionally receive and has taken part in science festivals and public conferences several times. "I like to give people some clues about what we are doing and not just give them nice pictures of Saturn. It is really rewarding."
Making it in Astronomy
According to Hébrard, one needs "a strong background in chemistry, physics, and applied science, and not only maths," to break into the field. Knowledge of astronomy, astrobiology, and planetary science is also key. But he also believes that having the right attitude toward astronomy research is even more important. What counts above all is motivation. "Anyone planning to break into the field should be well aware that rewards are purely scientific and be sure of their own motivations," he says, because astronomers have to deal with little funding and sometimes doubts from family and friends about the usefulness of their research. He also believes that astronomers need to be patient and able to work on remote things, with data that may take years to come back from a mission. Finally, he believes that "astrobiology, astronomy, and planetary science are fields of research that are very multidisciplinary; you need to be open-minded and curious and unafraid to explore unknown territories and new ideas."
The attitude Hébrard has toward his career is similar to the way he sees his research. One more thing he has learned while working by the side of more senior astronomers is to restrain his ambitions. "In the frame of such space missions as Cassini-Huygens, scientific rewards come indeed after many, many years ... and disappointment too. I can think of many people who would have been devastated if it was not for the mission's success."
So while he is hanging onto his dream "to get an academic position and be able to join a space mission programme from its beginning," he nonetheless keeps his feet firmly on the ground. He knows that to achieve his career ambition he will need be to be affiliated with either ESA or NASA, and such academic positions are rare. So although Hébrard advises anyone with a passion in astronomy to go for it, he warns that "keeping your eyes and mind open is a good way to start in such a research field." Whatever happens, "I will never regret working on this research," he says. "My only hope is to go on for as long as possible."
Elisabeth Pain is contributing editor for South and West Europe .