How I Killed Pluto and Why It Had It Coming

When I was a little girl, when anyone would ask me what I wanted to be when I grew up, I would always answer "an author or an astronomer".  It's as if I hadn't got past the A's in the list of all possible professions.

I've written a bit over my life, including countless business documents and many limericks.  I've co-authored a technical book and a Harvard Business Review article, had a little article make it onto Forbes.com, and am contributing book reviews to an upcoming book site.  And this modest blog is my effort to keep flexing those writing muscles.   I'm not by any means an author, but at least I've spent time writing.

But I've never done anything to follow up on that fascination with astronomy.  I didn't take an astronomy course during my undergraduate or graduate studies, and I was so incensed with University of Toronto's unwillingness to let me take Astronomy 100 purely for interest without an incredible amount of application red tape (despite holding a Masters in Mathematics), that I abandoned the attempt in a fit of pique.

Reading How I Killed Pluto and Why It Had It Coming by astronomer Mike Brown had me totally mesmerized.  It combined really elegant and easy-to-follow descriptions of the activities of the astronomers, science history and human interest in the form of a love story, petty chicanery on the part of scientific competitors, and the trauma of how Pluto got demoted.  It was wonderful.   The fact that I loved it so much (and kept reading until 4 a.m. to finish it) filled me with regret for not following up on this great passion from my childhood, but it also clarified for me how unhappy I would have been following a career path as a professional astronomer.  Brown casually describes a level of persistence in rigorous and yet rather plodding research that I would find hard to sustain.  But at least I can understand and relate to it.

Much of astronomy today is about highly exotic topics (at least to the layman), like whether the Big Bang was a singular event or whether we're in an oscillating world of multiple universes periodically colliding to create a Big Bang-like event.  Astrophysicists chase elusive particles that may only exist for nanoseconds, to learn more about the first moments of our universe.  The Large Hadron Collider at CERN has been trying to create the Higg's boson which is predicted by some wildly sophisticated particle physics theory.  I follow these things avidly (note my past paeans to TED talks about physics by Brian Greene and Brian Cox, here and here) but they are clearly beyond me.  I don't have the necessary understanding of physics to grasp more than just the superficial aspects of these studies.

Mike Brown's passion is much more within my grasp.  He looks for new planets, motivated by his early fascination with the night sky, not with the arcane details of particle physics.  I know there's a lot more to it, but his writing about planets and his attempt to find a new one is completely understandable by the lay person.  It brings back memories of what astronomy was about in my youth.  Ah, the joy of it.

I could relate to Brown's reference to the moon as his nemesis: a full moon makes star identification impossible and wipes out a possible night of work.  One of my great life experiences was a trip on the Big Island of Hawaii to the telescope cluster on Mauna Kea, and a subsequent stop part way down the mountain with our own powerful telescopes.  My husband and I were awed at the number of stars visible in the night sky - until the full moon rose above the horizon and ended the amazing sight.

The original meaning of planet was 'a wanderer'.  If you look at the sky night after night, the stars remain stationary, whereas the planets can be seen to move in their orbits.  So, to find a planet,  you have to look at the sky at different times and identify the object that has moved.  The original planets were identified because their movement was identifiable by eye alone:  the planets were big and their movement rather obvious.  Today, the identification involves comparing photographs of very tiny objects from powerful telescopes.  Software helps with narrowing things down, but ultimately what is involved is a dedicated and persistent astronomer eyeballing thousands of such images looking for an object that moved.

Brown believed that there could be planets beyond Pluto in the area called the Kuiper belt and booked computer time on telescopes to do a systematic survey of the skies.  Then, he (and other associates) would actually look through the photos, looking for a change in position that would signify a new planet.  Brown did this for years.

Starting in 1997, as a new young professor at Caltech, this was the central passion of Brown's professional life. In 2002,  he (well, really his grad student Chad Trujillo under his strategic direction) discovered an object (later named Quaoar) they initially thought was bigger than Pluto.  It turned out to be smaller than Pluto; being brighter than Pluto had made it look bigger.  In that same week, he got engaged, and received tenure at Caltech.  Things seem to come in threes for Brown.

The big three of Brown's career came in January 2005.  Brown and his team Chad Trujillo and David Rabinovitch, had three large objects that they had discovered and not yet announced.  Most astronomers gather information about their discoveries for a period of time before the official announcement.  This is partly to fully verify the discovery and partly to give the discoverer uncontested time to investigate before other astronomers rush in after the announcement.  Brown had come within a day of finishing a paper for publication about Santa, a large object out here Pluto, whose official name was K040506A based on date of discovery, when his first child, a daughter, made an early arrival.  In the following weeks of sleepless nights with a first baby, (and obsessive data collection on every aspect of the baby's activities), Brown never did complete the paper.  The discovery was to be announced at an international conference in the spring, and to maintain secrecy, the paper had an unassuming title, referencing an object code-named K040506A.  Just two days later, a group at a Spanish university announced the discovery of an object 2003 EL61 - and it turned out to be Brown's Santa.  It appeared that some chicanery was involved in that 'discovery' as later detective work showed that the Spanish group had accessed the computer logs of the Chilean telescope where Brown et. al. had made their discovery, likely through googling K040506A.  In naming this object Haumea (the name Brown submitted) and leaving the field blank for the name of the discovere, the IAU seemed to support Brown as the real discoverer.

Having been scooped Brown quickly prepared announcements about their other two discoveries, including the object that was slightly larger than Pluto.  These were later to be known as Eris and Makemake.

This put the astronomical establishment into a tizzy.  In Eris, had Brown discovered a tenth planet?  Or had this discovery shown that Pluto was just one of many trans-Neptune objects?  Back in 19th C, three large asteroids had been declared planets, only to be demoted when it was realized how many asteroids there were.  How could you declare an arbitrary cut-off for when something was not a planet?  Best to call them all just asteroids.

Despite how much he yearned to be the discoverer of a new planet, Brown argued that trans-Neptune bodies were similar to asteroids - a huge cluster of objects sharing somewhat similar characteristics and orbits quite different from the rest of the planets.  (Pluto had always been strange in having an orbit at a tilt to that of all the other plants).   Scientific rigor demanded that neither or both Eris and Pluto should be planets.  Brown argued that neither should be planets.

Demoting Pluto was an incredibly emotional and political decision, and one that was fought by a rearguard action of scientists, transforming a usually dull voting session of the International Astronomical Union into a cliff-hanger event.  They chose the word dwarf planet to describe both Pluto and Eris.

In reading this book, Brown emerges as a consummate teacher as well as a fine scientist.  He describes teaching an introductory Geology course during this frenetic time - something about which he knew nothing - so that he could learn about geology (another story that resonates with me, but that could be for another time).  Despite all that was going on his life during that time, he says this was his most enjoyable activity.   I think I would have liked to be in his class.

Did I mention I really really liked this book?  I highly recommend it.   I have a five-star rating system.  This time, I have to go all out with ten stars!

P.S. I happened to Stumble on this great web page (as a new user of Stumble Upon) which shows what several planets would look like to us if they were at the distance of the moon from Earth.