In Memory of Brian Marsden, Comet Discoverer Extraodinaire and Reporters’ Dream

Photo by Harold Dorwin

Not all accomplished scientists like talking to reporters, and not all of them are good at it. Brian Marsden embodied these rare characteristics: He was an amazing contributor to his field and he was approachable, helpful and kind, even on the tightest of deadlines. And so even though I never met the man, I feel his death as a personal loss.

Marsden was a supervisory astronomer at the Smithsonian Astrophysical Observatory and director emeritus of the Minor Planet Center.

Charles Alcock, director of the Harvard-Smithsonian Center for Astrophysics said in press release issued this afternoon that Marsden “was one of the most influential comet investigators of the 20th Century … and definitely one of the most colorful!”

He specialized in celestial mechanics and astrometry, collecting data on the positions of asteroids and comets and computing their orbits.

The comet prediction of which Marsden was most proud was that of the return of Comet Swift-Tuttle, which is the comet associated with the Perseid meteor shower each August. Swift-Tuttle had been discovered in 1862, and the conventional wisdom was that it would return around 1981. Marsden 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. He was right.

Marsden also played a key role in the “demotion” of Pluto to dwarf planet status. He once proposed that Pluto should be cross-listed as both a planet and a “minor planet,” and assigned the asteroid number 10000. That proposal was not accepted. However, in 2006 a vote by members of the International Astronomical Union created a new category of “dwarf planets,” which includes Pluto, Ceres, and several other objects. Pluto was designated minor planet 134340. The decision remains controversial.

That basic information, and much more biographical detail about Marsden, can be found at the Center for Astrophysics; I won’t repeat it here.

Instead, I’ll reprint two of our email exchanges in tribute to his candor and his helpfulness, along with links to the stories he helped me write. Goodbye, Brian Marsden. Thank you for all of your contributions, large and small.

July 2008, on reading a draft for a story about the new protocol being used to name Makamake, the fourth known dwarf planet …

Dear Anne,

Only one really substantive error, in the last paragraph under the second subheading:

“All except for the ones that orbit TWO times for Neptune’s every THREE times, that is. Those planets, locked into the same rhythm as Pluto, are to be named after underworld mythological deities.”

In the first paragraph of that section, since I am actually a member of both naming committees, it would perhaps be better to say:

“Brian Marsden has recorded the names of more than 12,000 asteroids and other planetary bodies during his 30-plus years at THE IAU’s Minor Planet Center. He IS ALSO THE SECRETARY OF the Committee on Small Body Nomenclature, one of the two IAU committees that must approve new dwarf planet names.”

One could argue that, given the chronologically earlier 2003 EL61, Makemake is the fifth dwarf planet, rather than the fourth.  But it is the fourth one to be named, and your second paragraph rather implies that.

And in the seventh paragraph, the point is that the naming came just a month after the IAU established the _name_ “Plutoid” for the category.  The category of dwarf planets (most of them to be transneptunian, together with the oddball Ceres) was actually defined two years ago, at the IAU General Assembly in Prague.

I liked the last paragraph: swindled or scooped, indeed!

But does Mike really want to be on record as a “believe[r] in astrology”?

Regards
Brian

In September of 2008, for another quirky dwarf planet naming story, about Haumea …

Anne Minard

Dear Anne,

You might say it is “a sort of compromise”.  After all, Mike Brown certainly discovered the satellites, and there is no evidence that the Spanish team found what they describe as the “discovery observations” of the primary (i.e., the observations of March 2003) before Mike Brown found the first of the satellites (in Jan. 2005).

Photo by Harold Dorwin

The leader of the Spanish team claims that the student usually credited with the discovery informed him of the discovery on 2005 July 25, which was 5-6 days after Mike Brown effectively announced the discovery in his AAS-DPS Abstract and 3-4 days before the Spanish team informed the Minor Planet Center of their discovery.  What I have always wanted to know is precisely _when_ the Spanish student actually first “saw” the March 2003 images, and what he did with this knowledge before informing his advisor.

Furthermore, Mike Brown had every right to propose names for the satellites, and it would be normal to have some connection between the names of the satellites and the name of the primary.

Without the answer to my question above, I don’t see how we can ever really completely resolve the issue.

Regards
Brian G. Marsden