I was born in Luton in 1954 and, after my parents moved to Norfolk when I was nine years old, educated at King Edward VII school in King’s Lynn. I started out on my scientific career with a mother passionate about education, and an inspiring school teacher excited by the beauty of mathematics. I studied mathematics and theoretical physics at Cambridge University between 1973–1976, and received my doctorate from the Cavendish Laboratory, Cambridge University, in 1979, on the subject of the cosmological evolution of extragalactic radio sources.
I joined the European Space Agency (ESA), in The Netherlands, as a research fellow in 1980. A year later, at the age of just 26, I was appointed as Project Scientist for the recently-adopted Hipparcos space astrometry mission, which I subsequently headed as lead scientist between 1981–1997. Leiden, a beautiful city in The Netherlands, would be the home for me and my family ― my wonderful wife Julia and our three sons Thomas, James and Richard ― for the next 30 years!
Astrometry was a new field for ESA. My work involved overall coordination of the scientific aspects of the satellite design, manufacture and testing, assisting with the parallel preparation of the input catalogue and overall data analysis, and chairing the Hipparcos Science Team. Like all space missions, Hipparcos presented a continuous series of difficult challenges, tackled in collaboration with a wonderful and highly motivated team of scientific colleagues across Europe, project managers in ESA, and talented engineers in European industry. After its launch in 1989, the satellite failed to reach its target geostationary orbit, and I also took over the overall mission management with the numerous associated recovery operations. It was a tense, difficult and protracted period. But, executed by independent data analysis teams, the project eventually recovered all and more of its original scientific objectives, thereby validating the concepts and principles underpinning space astrometry. One of the many high points was our presentation of the final Hippacos star catalogue to the international scientific community at a major conference in Venice in 1997.
In 1993, together with Lennart Lindegren, I jointly proposed a more ambitious astrometry mission to take advantage of technological advances such as CCDs, large lightweight ceramic mirrors and structures, and micro-Newton gas thrusters. This built on earlier ideas put forward by Erik Høg and Lennart Lindegren. The mission was approved by ESA’s Science Programme Committee in 2000. I was the scientific leader of the Gaia project from its inception until shortly before the Critical Design Review in 2008, establishing the payload concept, its technical feasibility, its operational and data analysis principles, its organization structure, and coordinating its enormous scientific case. This all led to its successful launch in 2013, just one year after the date targeted at the time of its adoption in 2000.
Now eight years into its operational lifetime, Gaia is generating progressively improved catalogues of more than two billion stars in our Galaxy, leading to an exquisitely detailed portrait of our Galaxy and its formation, with impacts on all branches of astronomy and astrophysics. Amongst its expected scientific impacts, I have been a proponent of the discovery potential for exoplanets with Gaia, predicting that many thousands could be detected by the end of this decade. What is of enormous satisfaction to me today is reading the very large numbers of scientific papers that are being published based on the Gaia survey, and admiring their ingenuity, their breadth, and the huge scientific advances that they represent. Gaia is, today, regarded as a revolution in astronomy, and I am delighted to have played my part in its success.
In parallel with my duties in ESA, I held a position as Professor of Astronomy at Leiden University from 1993 to 2009. Post ESA, in 2010, I held a joint position at Heidelberg University and the Max Planck Institute for Astronomy, spending a wonderful year in Heidelberg, where I worked on the first edition of my “Exoplanet Handbook”. Since 2012, I have been adjunct professor at University College Dublin. In other memorable and stimulating appointments and scientific interludes, I was Bohdan Paczynski visiting professor at Princeton University in 2013; holder of the Källén Seminar for Breakthrough Discoveries, University of Lund (Sweden) in 2014; visiting fellow at the Kiepenheuer Institute for Solar Physics, Freiburg (Germany) in 2016, and visiting scientist at the Instituto Astrofísica Andalucía (IAA), Granada in 2017. I was most fortunate that my wife, Julia, could join me on all of these adventures.
I am of course most grateful to the Shaw Prize Foundation for their recognition of my contributions to space astrometry, which I am delighted to share with my long-term colleague Lennart Lindegren. And let me also stress the self-evident: that the major scientific advances gained by Hipparcos and Gaia could only have come about through the dedicated and outstanding contributions of many others ― scientists, managers, and engineers ― over very many years.
29 September 2022 Hong Kong