The Jewel on the Mountaintop The European Southern Observatory through Fifty Years Claus Madsen The Jewel on the Mountaintop Fifty Years of the European Southern Observatory Claus Madsen Acknowledgement: As a title, The Jewel on the Mountaintop is derived from a speech by Swiss Ambassador Jean-Pierre Keusch at the inauguration of the 3.5-metre New Technology Telescope (NTT) on 6 February 1990. The NTT was, in many ways, a precursor to the Very Large Telescope, which — staying with the metaphor — constitutes the true jewel on the mountaintop. Cover Photo: Dawn at Paranal — the first rays of the Sun are reflected by the telescope enclosures at Paranal. (Photo: Gerd Hüdepohl) ADRIAAN BLAAUW In Memoriam Table of Contents Author’s Preface 9 Prologue 15 The Hinge: The VLT 15 Part I: Catching Up 19 Chapter I-1 ∙ The Oldest Science 21 Chapter I-2 ∙ Returning from the Abyss 25 Chapter I-3 ∙ A Dramatic Twist 35 Chapter I-4 ∙ In the Most Remote Place God Could Find 43 Chapter I-5 ∙ ESO — Quo Vadis? 53 Chapter I-6 ∙ Towards the 3.6-metre Telescope 59 Chapter I-7 ∙ Sky Mapper 75 Chapter I-8 ∙ Of Heaven and Hell, the Vatican and the Mission 85 Chapter I-9 ∙ The Changing of the Guard 93 Chapter I-10 ∙ Garching United 99 Part II: Years of Experimentation 107 Chapter II-1 ∙ Upping the Ante 109 Chapter II-2 ∙ Inventing a Game Changer 119 Chapter II-3 ∙ EMMI, SUSI, SOFI and the other Darlings 125 Chapter II-4 ∙ Hubble at ESO 137 Chapter II-5 ∙ History in Passing 147 Chapter II-6 ∙ An Annus Mirabilis 155 Chapter II-7 ∙ Decision Day 171 Chapter II-8 ∙ A Mountain in the Middle of Nowhere 177 Chapter II-9 ∙ NTT First Light 187 Part III: The Breakthrough 199 Chapter III-1 ∙ Back to the Drawing Board 201 Chapter III-2 ∙ Aux Instruments, Chercheurs! 215 Chapter III-3 ∙ Breaking the Seeing Barrier 231 Chapter III-4 ∙ From double-sight to supersight: Interferometry 243 Chapter III-5 ∙ The Return of the Dalton Brothers 251 Chapter III-6 ∙ Bang for the Buck 265 Chapter III-7 ∙ Paradigm Revisited 271 Chapter III-8 ∙ Upgrading, De-scoping 279 Chapter III-9 ∙ Clouds on the Horizon 289 Chapter III-10 ∙ At the Brink 295 Chapter III-11 ∙ Tranquillity in Chile, Icy Winds in Europe 305 Chapter III-12 ∙ Tuning a Formidable Science Machine 317 Chapter III-13 ∙ The Countdown 327 Chapter III-14 ∙ Clear Skies, at Last 337 Chapter III-15 ∙ First Fringes of the Phoenix 351 Chapter III-16 ∙ Not just a Telescope, an Observatory; Not just an Observatory, a Home 361 Part IV: Towards New Horizons 367 Chapter IV-1 ∙ ALMA 369 Chapter IV-2 ∙ Into New Territory 393 Chapter IV-3 ∙ Buds at Paranal 401 7 Chapter IV-4 ∙ Of Eponymous Birds and Euros 411 Chapter IV-5 ∙ The VLT in Retrospect 427 Chapter IV-6 ∙ A Love Affair 445 Chapter IV-7 ∙ A Growing Organisation 451 Chapter IV-8 ∙ The Surge 457 Chapter IV-9 ∙ Born in Europe, at Home in the World 487 Chapter IV-10 ∙ A Window to the Public 501 Epilogue 513 References 517 Appendices 527 Appendix 1 ∙ Important Milestones 529 Important milestones during the period covered in Part I 529 Important milestones during the period covered in Part II 531 Important milestones during the period covered in Part III 532 Important milestones during the period covered in Part IV 533 Appendix 2 ∙ List of ESO Council Presidents and Directors General 535 Appendix 3 ∙ List of Interviewees 537 Appendix 4 ∙ List of Acronyms 538 Appendix 5 ∙ Index of Names 543 Appendix 6 ∙ Subject Index 550 8 Author’s Preface n early 1988, my supervisor at ESO, Richard West, called me to his office, where II met with Adriaan Blaauw, who had served as ESO’s second Director General, succeeding Otto Heckmann. Richard explained that Adriaan had begun to work on a series of articles about the early years of the organisation at the suggestion of ESO’s then Director General Harry van der Laan. These articles had originally been intended for The ESO Messenger, but had soon turned into a book project, and Richard asked me to assist Adriaan in particular with pictures. Richard had served under Adriaan and it was clear that great respect and mutual sympathy existed between the two. Richard wanted to extend all the help he could to Adriaan in his new undertaking. During the months to come I did my best to help, but the task soon changed from one simple job among many to a deeply fascinating assignment that enabled me to obtain a deeper insight into ESO’s history as told not just by an insider, but by someone of the impeccable academic and human stature that has always characterised Adriaan. It was an intellectual feast that I have never forgotten. I had joined ESO only eight years earlier as a member of what was then called the ESO Sky Atlas Laboratory. The main task of the laboratory was to produce the ESO Survey of the southern skies, based on large photographic glass plates obtained with the ESO 1-metre Schmidt telescope at the La Silla Observatory and later also, together with the UK’s Science Research Council (SRC), the ESO/SRC Deep Sur- veys, a task that also involved the UK Schmidt Telescope at Siding Spring in New South Wales, Australia. All in all, the task of the laboratory took more than 20 years to complete. My own task was peripheral to the main job, but it included developing techniques to enhance the exploitation of the tremendous scientific treasures that were contained in these glass plates. Furthermore, I had become interested in, and made a bit of a name for myself in, wide-field imaging techniques and their applica- tion to astronomy. But when Adriaan began his book project my professional path had taken a twist. In 1986, ESO established an information service and Richard, who had been in charge of the laboratory, was appointed head of this new service. He asked me whether I would like to follow him into this new endeavour, and this enabled me to pursue another interest of mine, the public awareness of science and, more generally, the interaction between science and society, topics that were to deter- mine my continued career for the decades to come. 9 The Jewel on the Mountaintop Adriaan’s book was published in 1991. Although it was a history tracing the earli- est years of ESO, it appeared to me as almost eerily timely, for at the time ESO was passing through a rough patch as we struggled with the challenges of the recently approved Very Large Telescope (VLT) project. His precise description of the diffi- culties in the 1950s and 1960s provided both food for thought and a good under- standing of the challenges ahead — but also of the ingenuity, tenacity and immense dedication displayed by everyone who had been associated with the great adventure that we now label rather summarily ESO. This is perhaps the most important les- son learnt from what we now call an adventure and the “five-star success” (Flensted Jensen, 2002) that has enabled the strong comeback of European astronomy: success does not come by itself. Rather it is the result of a mechanism that can foster, absorb and bring to fruition great ideas, wherever they may be. Many battles were fought, many mountains climbed (also literally), many hurdles overcome — some which are widely known, others which will remain known to only a few. Some which deserve scrutiny because lessons can be learnt from them, others that deserve little more than to disappear in the mist of forgotten times. Meanwhile, many years have passed. In December 2009, ESO’s Director General, Tim de Zeeuw asked me if I would be interested in writing a new book about ESO’s fascinating history — focussing on the more recent period that Blaauw for obvious reasons could not cover. I gladly accepted the offer and the challenge. I have been privileged to follow ESO’s evolution for more than 30 years, and in connection with the 40th anniversary actually produced a video about ESO’s history. With this back- ground, and in preparation for this book, I have carried out extensive interviews with key actors, both from inside and outside the organisation, trying to obtain a more comprehensive understanding of ESO’s role and evolution. These interviews and conversations have been invaluable and I am more than pleased to acknowledge the many people who have given me their time, and their voices, telling me their version of the ESO story. A complete list of interviewees is given in Appendix 3. The interviews have complemented the treasure trove of information found inThe ESO Messenger, the quarterly magazine that has been published since 1974 (and now amounting to a staggering 10 000 pages), the Annual Reports, minutes of the ESO Council and Committee meetings and a myriad of other publications from ESO. Of course, with such rich material, the challenge has been that of selection. It is the hard job, but also the prerogative of the author, to make the choices. I have done so knowing that others might have chosen differently. 10 Author’s Preface This book sees ESO’s development as falling into four distinct phases: Catching Up (1962–1980), Years of Experimentation (1980–1990), The Breakthrough (up until the VLT’s inauguration and science operations, and also first fringes at the Very Large Telescope Interferometer [VLTI]), and finally, Towards New Horizons (up until 20071), when ESO began to set the research agenda through new and unique projects.