Brian G. Marsden (1937-2010)

Word rocketed through the astronomical community today that Brian Marsden had died after a prolonged illness.

Marsden served as the long-time director of the IAU's Central Bureau of Astronomical Telegrams (until 2000) and its Minor Planet Center (until 2006), positions that effectively made him and his small staff the worldwide clearinghouse for astronomical discoveries.

Astronomer Brian Marsden stands next to the 15-inch "Great Refractor," housed a few steps away from his office at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts.
CFA / Harold Dorwin
We at Sky & Telescope had a special closeness to Marsden, and not simply because his office at the Harvard-Smithsonian Center for Astrophysics was within easy walking distance. He was perpetually busy, his desk a maelstrom of paperwork piled in chaotic-looking bundles that defied logical organization. Yet he always found time to answer our questions, often stretching what should have been a quick, 5-minute update into wide-ranging chats that would go on for a half hour or more.

One thing I'll remember most was his encyclopedic knowledge of the solar system and its contents. Whether dates and places or eccentricities and semimajor axes, he had uncanny recall. I'll also treasure his support of amateur astronomers and the value of the high-quality observations they often made and reported to him.

As it turns out, a few years ago Marsden wrote down the highlights of his long and distinguished career "just in case." Earlier today Gareth Williams, assistant director of the MPC (and Marsden's son-in-law), added some updates and posted the autobiographical reflection as a Minor Planet Electronic Circular. What follows is a somewhat shorter version of that.

No doubt many of you knew Marsden personally or through his many contributions to solar-system dynamics. If so, feel free to add a comment at the end.

Brian Geoffrey Marsden was born on August 5, 1937, in Cambridge, England. His father, Thomas, was the senior mathematics teacher at a local high school. It was his mother, Eileen (nee West), however, who introduced him to the study of astronomy, when he returned home during his first week in primary school in 1942 and found her sitting in the backyard watching an eclipse of the Sun. What most impressed the budding astronomer was not that the eclipse could be seen, but the fact that it had been predicted in advance, and it was the idea that one could make successful predictions of events in the sky that eventually led him to his career.

When, at the age of 11, he entered the Perse School in Cambridge he was developing primitive methods for calculating the positions of the planets. Together with a couple of other students he formed a school Astronomical Society, of which he served as the secretary. At the age of 16 he joined and began regularly attending the monthly London meetings of the British Astronomical Association. He quickly became involved with the Association's Computing Section, which was known specifically for making astronomical predictions other than those that were routinely being prepared by professional astronomers for publication in almanacs around the world.

He was an undergraduate at New College, University of Oxford. In his first year there he persuaded the British Astronomical Association to lend him a mechanical calculating machine, allowing him thereby to increase his computational productivity. By the time he received his undergraduate degree, in mathematics, he had already developed somewhat of an international reputation for the computation of orbits of comets, including new discoveries. He spent part of his first two undergraduate summer vacations working at the British Nautical Almanac Office.

After Oxford, he took up an invitation to cross the pond and work at the Yale University Observatory. He had originally planned to spend just a year there carrying out research on orbital mechanics, but on his arrival in 1959 he was also enrolled as a Yale graduate student. With the ready availability of the university's IBM 650 computer in the observatory building, he had soon programmed it to compute the orbits of comets. Recalling his earlier interest in Jupiter's moons, he completed the requirements for his Ph.D. degree with a thesis on The Motions of the Galilean Satellites of Jupiter.

Brian Marsden joined the Smithsonian Astrophysical Observatory in 1965 and became director of the IAU's Central Bureau for Astronomical Telegrams in 1968.
S&T: Dennis Milon
At the invitation of director Fred Whipple, he joined the staff of the Smithsonian Astrophysical Observatory in Cambridge (the one in Massachusetts) in 1965. Whipple was probably best known for devising the "dirty snowball" model for the nucleus of a comet a decade and a half earlier. At that time there was only rather limited evidence that the motion of a comet was affected by forces over and above those of gravitation (limited because of the need to compute the orbit by hand), and the Whipple model had it that those forces were due to the comet's reaction to vaporization of the cometary snow or ice by solar radiation. Marsden therefore developed a way to incorporate such forces directly into the equations that governed the motion of a comet. It is noteworthy that the procedure devised and developed by Marsden is still widely used to compute the nongravitational effects of comets, with relatively little further modification by other astronomers.

The involvement of the Smithsonian Astrophysical Observatory with comets had been given a boost, shortly before Marsden's arrival there, by the transfer there from Copenhagen of the Central Bureau for Astronomical Telegrams, a quaintly named organization that was established by the International Astronomical Union soon after its founding in 1920. The CBAT is responsible for disseminating information worldwide about the discoveries of comets, novae, supernovae and other objects of generally transient astronomical interest. It is the CBAT that actually names the comets (generally for their discoverers), and it has also been a repository for the observations of comets to which orbit computations need to be fitted.

Marsden succeeded Owen Gingerich as the CBAT director in 1968. He was joined by Daniel Green as a student assistant a decade later, and Green took over as CBAT director in 2000. Until the early 1980s the Bureau really did receive and disseminate the discovery information by telegram (with dissemination also by postcard Circular), though email announcements then understandably began to take over. The last time the CBAT received a telegram was when Thomas Bopp sent word of his discovery of a comet in 1995. Since word of this same discovery had already been received from Alan Hale a few hours earlier by email, the object was very nearly just named Comet Hale, rather than the famous Comet Hale-Bopp that beautifully graced the world's skies for several weeks two years later.

The comet prediction of which he was most proud was of the return of Comet Swift-Tuttle, associated with the Perseid meteors each August. It had been discovered in 1862, and the conventional wisdom was that it would return around 1981. He followed that line for much of a paper he published on the subject in 1973. He had a strong suspicion, however, that the 1862 comet was identical with one seen in 1737, and this assumption allowed him to predict that Swift-Tuttle would not return until late 1992. This prediction proved to be correct, and this comet has the longest orbital period of all the comets whose returns have been successfully predicted.

Although the CBAT also traditionally made announcements of the discoveries of asteroids that came close to the earth, the official organization for attending to discoveries of asteroids is the Minor Planet Center. Also operated by the International Astronomical Union, the MPC was located until 1978 at the Cincinnati Observatory. In that year the IAU asked Marsden also to take over the direction of the MPC. At the end of 1989, Gareth Williams joined the MPC staff and later became its associate director.

The advances in electronic communication during the 1990s also permitted improvements in MPC operation. Perhaps the most important of these was the online introduction, in 1996, of the Near-Earth Object Confirmation Page. This draws attention to candidate Earth-approaching objects in need of follow-up observations as soon as they have been reported to the MPC.

In 1998 Marsden gained a certain amount of notoriety by suggesting that an object called 1997 XF11 could collide with Earth. But he did this as a last-ditch effort to encourage the acquisition of further observations, including searches for possible data from several years earlier. The recognition of some observations from 1990 made it quite clear that there could be no collision with 1997 XF11 during the foreseeable future. Without those 1990 observations, however, the object's orbit would have become very uncertain following a close to moderate approach to Earth in 2028. Indeed, Marsden correctly demonstrated that there was the possibility of an impact in 2040 and in several neighboring years. He was thereby able eventually to persuade his principal critics routinely to perform similar uncertainty computations for all near-earth objects as they were announced.

Marsden was particularly fascinated by a family of comets, known as the Kreutz group, that pass close to the Sun. The discovery of three more of these sungrazing comets in the mid-20th century led him to undertake a detailed examination of how the individual comets might have evolved from each other. He published this examination in 1967, following it up with a further study in 1989 involving a more recent bright Kreutz comet, as well as several much fainter objects that had been detected from Sun-observing coronagraphs out in space. Beginning in 1996, these were being found by the SOHO coronagraphs at rates ranging from a few dozen to more than 100 per year. Unfortunately, the faintness of the comets and the poor accuracy with which they could be measured made it difficult to establish their orbits as satisfactorily as Marsden would have liked. More significantly, however, he was able to recognize that the SOHO data also contained another group of comets with similar orbits, these comets now known as members of the "Marsden group". Unlike the individual Kreutz comets, which have orbital periods of several centuries, it seems that the Marsden comets have orbital periods of only five or six years.

Although their views on Pluto's status were worlds apart, Clyde Tombaugh (left) and Brian Marsden were all smiles during this meeting outside Harvard Observatory in September 1987.
S&T: J. Kelly Beatty
Another series of astronomical discoveries that greatly interested him were what he always called the "transneptunian objects", though many of his colleagues have insisted on calling them "objects in the Kuiper Belt". When what those same colleagues considered to be the first of these was discovered in 1992, Marsden immediately remarked that this was untrue, because Pluto, discovered in 1930 and admittedly somewhat larger in size, had to be the first. More specifically, he was the first to suggest, correctly, that three transneptunian objects discovered in 1993 were exactly like Pluto in the sense that they all orbit the Sun twice while Neptune orbits it thrice. This particular recognition set him firmly on the quest to "demote" Pluto. Success required finding transneptunian objects more comparable to Pluto in size, something that finally happened in 2005 with the discovery of Eris. At its triennial meeting in 2006 in Prague, the IAU voted to designate these objects, together with the largest asteroid, Ceres, and two other transneptunian objects now known as Makemake and Haumea, members of a new class of "dwarf planet."

It was also at the IAU meeting in Prague that Marsden stepped down as MPC director, and he was quite entertained by the thought that both he and Pluto had been retired on the same day. While he remained working at the MPC (and also the CBAT) in an emeritus capacity, the directorship was passed to Timothy Spahr, who joined the MPC in 2000.

Marsden served as an associate director of the Harvard-Smithsonian Center for Astrophysics for 15.75 years from the beginning of 1987 (the longest tenure for any of the Center's associate directors). He was chair of the Division of Dynamical Astronomy of the American Astronomical Society during 1976-78 and president of the IAU commissions that oversaw the operation of the Minor Planet Center (1976-79) and the Central Bureau for Astronomical Telegrams (2000-03). He continued to serve subsequently on the two solar-system nomenclature committees of the IAU, being the perennial secretary of the one that decides on names for asteroids. Although known worldwide as a theorist and dynamicist, he shares discovery credit (with Nikolai Chernykh) for asteroid 37556 Svyaztie.

Among the various awards he received from the U.S., U.K., and other European countries, the ones he particularly appreciated were the 1995 Dirk Brouwer Award (named for his mentor at Yale) of the AAS Division on Dynamical Astronomy and the 1989 Van Biesbroeck Award (named for an old friend and observer of comets and double stars), then presented by the University of Arizona, now by the AAS, for service to astronomy.

25 thoughts on “Brian G. Marsden (1937-2010)

  1. Patrick Wiggins

    A real loss to the astronomical community indeed. Both professional and amateur.

    Judging from the many comments on various email lists I’ve read I was not the only amateur that Brian helped get into minor planet astrometry. It never failed to amaze me that despite the high position he held and his busy schedule he was always willing to answer his own phone and talk to even rank amateurs like me. Heck, he even named a minor planet for me.

    He will be missed.

    I will miss him.


  2. Richard Kowalski

    Brian was the first person that many amateurs contacted and in most cases the first to respond when they started to interact with the professional astronomers. Brian’s gentle encouragement and guidance lead these amateurs into doing useful science from their backyards.

    An so was the case for me in 1997 when I first contacted the MPC. A short time later I had the silly idea of starting the Minor Planet Mailing List to facilitate communications between myself and others observing asteroids. Brian announced the start of the list in an Editorial MPEC and rapidly hundreds of amateurs and professionals working in the field subscribed. I was lucky enough to meet him at Lowell Observatory a few years later.

    From that simple and generous beginning that he helped to foster, I’ve been able to obtain my dream and work at a job I love at a place I wanted to be since I was 13.

    Thank you Brian.

    Richard Kowalski
    Catalina Sky Survey
    Lunar and Planetary Laboratory
    University of Arizona

  3. Laurel Kornfeld

    I met Marsden at the Great Pluto Debate in February 2007 in Brookline, MA, where he was one of the speakers. We had a very friendly debate over Pluto on the day of the Superbowl (the event ended before the game started). He was wrong in his quest to demote Pluto, and I wish he had lived long enough to see the New Horizons mission and the undoing of everything that took place in Prague in 2006, because these things will happen. Dwarf planets are not minor planets; that is a term used for asteroids. Dwarf planets are a third class of planets; Tombaugh was right. I wish both of them were still here; that would make for some fascinating discussion.

  4. Doc Clay

    My heart is incredibly heavy; I got to know Dr. Marsden in 1970 when I first started the observatories here in Arkansas (Arkansas Sky Observatories – ASO) and we had many, many late night telephone conversations before the days of internet, faxes and other modern forms of communications.

    The old dial phone in the observatory office would ring.
    “Um….Clay Sherrod? Hello Clay?” the distinctively accented voice would always begin.

    There would always be a chuckle; no doubt it was Brian Marsden.

    “I wonder if you might have clear skies tonight? There may be a new [comet/nova/ fill in the blank] for you to confirm for us. It may be nothing, but I hope that you can have a look! If you can, of course.”

    He became a good friend and mentor, as he has to many people throughout the community of astronomy.

    In all, Brian was one of the finest men that I have ever known and an astronomer that the world will never replace.

    This field of the tiny worlds of our solar system is not going to be the same without him.
    Lord, I cannot believe he is gone…..

    …but our skies have gained the brightness and sparkle that is Dr. Brian Marsden. We should strive to remember him, miss him, with every sungrazing comet that graces the Heavens.

    P. Clay Sherrod

  5. Marsden Fan

    O Laurel, how sad that you did this… It does you no good at all, neither your cause nor yourself as a person.

    Setting that aside…

    THREE CHEERS TO BRIAN MARSDEN!!! He was always so perceptive and intelligent, and a generous soul. May he rest well.

  6. Hal Weaver

    I was deeply saddened by the news about Brian. He was my “go to” guy for advice about comets, especially newly discovered ones, for more than 30 years. No matter what time of the day or night I contacted him, his reply was never far behind, supplying critical information to enable my observations. When I was on Kitt Peak in 1983 trying to get a bead on comet IRAS-Araki-Alcock, Brian even called my house and relayed through my wife the latest word on where that Earth-grazer was headed. (She loved his British accent!) And Brian was the one who recommended that I observe 103P/Hartley 2 during the first spectroscopic observations of a comet by the newly commissioned Hubble Space Telescope in September 1991. I’ll be forever grateful to Brian for his sage advice, and the warmth with which he delivered it. Ultimately we’re all “cosmic dust”, but Brian is special “comet dust” whose memory will last forever. We miss you terribly, dear friend.

  7. Paulo Holvorcem

    A great loss to science and the astronomical community. May Brian rest in peace, after having used so productively his time on earth. My condolences to his family and friends.

    Brian Marsden’s articles in the mid-1990s mentioning the insufficient amount of astrometric follow-up observations being done at the time motivated me (who until then had only done theoretical and computational research) to obtain my first observatory code and start observing NEOs and comets with a 20-cm telescope and a CCD camera, back in 1996. From these small beginnings, many observational and software projects arose, and I even got to discover a few NEOs and comets in collaboration with good people (like Michael Schwartz and Charles Juels) I would not have met without that initial step into minor planet and comet observing. One may say that Brian’s influence changed the course of my life toward solar system astronomy, and this was a change for the best. For this I will always be thankful to him.

    Paulo Holvorcem
    Porto Seguro, Brazil

  8. Phil Perry

    Brian Marsden did great work for the astronomical community. My only complaint is that he and his associates were irresponsible in publicly announcing impending collisions with asteroids, based on very preliminary orbits. This would lead to screaming headlines about “We’re All Going to Die!!!”, followed a few days later by announcements of the form “Never mind!”. This has helped lead to great public disrespect for science in general, and astronomy in particular. What is going to happen when something is REALLY on a collision course? The warnings will be dismissed as “more Chicken Little” and “the Boy is Crying Wolf again”. Surely there is a way to ask for pre-discovery images without giving a humanity’s Expiration Date? That’s all I’m asking — don’t give collision dates (that will unduly excite the infotainment industry) until a final orbit is determined and a substantial risk of catastrophe is found to exist. That would be the responsible thing to do.

  9. David Chandler

    I helped to get Brian in trouble with his colleagues, and it’s a tribute to his general conviviality and good-heartedness that he never held it against me. During the first day of the report on XF11, I pushed him hard to give a first-order estimate of the impact probability, and he gamely carried out a basic back-of-the-envelope calculation as we spoke, which I used (with all due explanation of its roughness) in my Boston Globe story. Many astronomers were, and remained for a long time, angry at Brian for communicating honestly with the press about that impact possibility — the first one ever to be predicted — but I felt then and still do that he did things exactly correctly, and he stood by what he had said despite a lot of criticism that in my opinion was quite unfair.
    I will miss Brian deeply. I can almost hear his hearty laughter rolling out through the solar system.

  10. Sam Storch

    I note with sadness the passing in the same week of both Brian Marsden and Allan Sandage. The close proximity of the loss of these two “giants” is notable- Brian Marsden was the “living symbol” of the discipline and knowledge in through celestial mechanics, and Sandage was similarly the “dean of observational cosmology.”

    In just a few days, the “old” and the “new” astronomy each lost the one person who could command the attention of an entire room merely by walking in!

    It is now up to the rest of us to adequately publicize, fund, and support the continuing basic research these scientists represented- not for the sake of financial profit, but for the sake of human curiosity, the single reason anyone is reading this page!

  11. James W. Young

    Brian was never without encouragement to all of us,
    amateurs and professionals, who were influenced by
    his graciousness and willingness to move the work
    of the Minor Planet Center forward. Thank you Brian,
    you will be sorely missed by everyone in the universe!
    Those who follow him in the work he so expertly began,
    will undoubtedly feel his guidance forever.

  12. John Hacker

    I’m a reporter for a small newspaper in Southwest Missouri and Mr. Marsden always made time to talk to me. I would call him for comment when a new comet that might be visible came by and like with the guys at Sky and Telescope, he always made time and, even with an amateur like me, managed to turn what could have been two or three minutes on the phone into a half an hour discussion. He was a very patient man and very easy to work with. He will be missed.

  13. Christine Pulliam

    It was my privilege to work with Brian in the 9 years since I came to the Center for Astrophysics. Every interaction with him was a pleasure. As others have noted here, he was a great scientist with a sparkling wit and wonderful sense of humor. The world is a grayer place without him.

    Ross – Not to worry, Brian already has an asteroid named in his honor (1877 Marsden).

  14. Laurel Kornfeld

    Marsden Fan, you misunderstand. I had a great conversation with him that day in 2007 and wish there could be more. His support of demoting Pluto is part of who he was, and disagreeing with it doesn’t mean I respect him less. 73 is too young to die in this day and age, and I wish he had lived much longer. The people who take part in these fascinating discussions give a part of themselves to those discussions, which is what makes the ongoing conversation so interesting and so human. I am very sorry for his loss from the astronomy community. But I also believe he would want friendly discussions and debates to go on, as that was a part of who he was. If I offended anyone with my statement above, I sincerely apologize.

  15. JLA

    A giant of astronomy has passed, what a great loss. I only met him once, during his Brower lecture in the 1996 DDA meeting. He explained the most complicated terms in dynamical astronomy (von Zeipel methods, etc) in a most humorous and jovial way. He will be missed.

  16. Joe Rao

    Brian Marsden was one of the nicest persons I’ve ever met.

    He was invaluable to me in providing critical data in the preparation for my feature articles in Sky & Telescope for both the Perseid and Leonid Meteor Showers, but more importantly, he became a good friend.

    The great thing about Brian was that it didn’t matter to him if you were a reporter from a 250-watt radio station in a 300-market or from CNN International. He would give you the same amount of time and consideration and answer any question you might have. He loved sharing his knowledge with anyone who would listen.

    For this reason, the news media gravitated to him like moths might be attracted to a flickering light.

    Here in New York, for many years, the news media had access to had Ken Franklin, the Chief Astronomer at the Hayden Planetarium who was very much cut from the same cloth as Brian After Ken passed way in 2007 I said to myself that ” . . . at least we still have Brian Marsden.” Now, Brian is gone too. Very sad!

    As those of the Jewish faith might say, he was a real mensch.

  17. Jim Eckendorf

    I found an object in my Variable star field, woke up another observerver who confirmed something was there. Brian was able to let me know that I had rediscovered a minor planet. DO NOT FORGET HIS value to AAVSO

  18. Jim Franklin

    I spoke to Brian Marsden many years ago when a very keen and active amateur, before the world of adulthood got in the way. I found Brian to be very patient and supportive, despite me being a bit of a precocious teen, and his kind words, support and insight certainly earned unswerving and life long respect for a great man.

    His contributions to the science of Astronomy cannot be downplayed and he is a very sad loss.

    My condolences go out to family and friends on this very sad news.

  19. Charles Morris

    I have had the honor of knowing Brian for at least 35 years. When I lived in the Boston area in the late 70′s & early 80′s I saw Brian frequently when I was working with Dan Green (who worked with Brian at CBAT) on the International Comet Quarterly. Brian always had fasinating stories about CBAT (the clearing house for comet discoveries) and astronomy, in general. But it was more than professional. I also had the honor of being invited to Brian’s house on a number of occasions where I got to know different sides of Brian and his family. But Brian was Mr.Comet to many of us. Although his love was orbit computation, I did find an actual comet observation, complete with magnitude estimate in the BAA records from the 1950′s! Another memory of Brian was at Division of Plantary Science meetings…wherever he went, there would be a swarm of people orbiting him. He was an astronomical superstar in a way and certainly well-known to the media. His distinctive British accent and manner were unmistakeable. The astronomical world…specifically, the comet and minor planet world has lost a giant in our field. And I lost a long-time friend.

  20. Martin George

    I met Brian on only a few occasions, most recently in Prague in 2006, chatting with him for the last time at Heathrow airport not long after the Pluto decision. He was one of the great gentlemen of science who contributed so very much to our knowledge and understanding. He will be greatly missed.

  21. Wally

    I became interested in minor planets and comets back in the 60s and 70s and had the opportunity to correspond with Brian Marsden numerous times . The CBAT was where a lot of the action was happening in the astronomical world about the small bodies of the solar system.

    I’ll never forget the semiperiodic postcards, some difolds or trifolds, that were the Circulars in those days. Or calling in to the CBAT and also sending a telegram about the discovery of Nova (V1500) Cygni 1975 to the Bureau.

    He was kind enough to alert people to early manually calculated predictions I made of occultation of stars by minor planets.

    I had the privilege of meeting him several times in the 1980s including the 50th anniversary meeting of Pluto’s discovery in Tucson. He was always a charm to listen to and you always learned something from him you didn’t know about either astronomy or astronomers.

    He was a true believer that we all contributed to astronomy, whether amateur, student or professional astronomer.

  22. Wally

    I became interested in minor planets and comets back in the 60s and 70s and had the opportunity to correspond with Brian Marsden numerous times . The CBAT was where a lot of the action was happening in the astronomical world about the small bodies of the solar system.

    I’ll never forget the semiperiodic postcards, some difolds or trifolds, that were the Circulars in those days. Or calling in to the CBAT and also sending a telegram about the discovery of Nova (V1500) Cygni 1975 to the Bureau.

    He was kind enough to alert people to early manually calculated predictions I made of occultation of stars by minor planets.

    I had the privilege of meeting him several times in the 1980s including the 50th anniversary meeting of Pluto’s discovery in Tucson. He was always a charm to listen to and you always learned something from him you didn’t know about either astronomy or astronomers.

    He was a true believer that we all contributed to astronomy, whether amateur, student or professional astronomer.

  23. Mike Nofi

    I am so disappointed to see that some people are using the passing of Brian Marsden as an oppertunity to express their politically motivated views during a time when we should be reflecting on Brian’s contribution to astronomy. I find this kind of behavior to be selfish and disrespectful. During most of my life Brian was the communication hub for new discoveries for both the professional and amateur astronomical communities. He will be sorely missed.