This is a breezy memoir by a Caltech astronomer, Mike Brown,
about how he discovered the major new bodies in the outer solar system: Quaoar, Sedna, Haumea, Makemake, and the biggest of all, Eris. The book is available here. Eris is actually larger than Pluto, and prompted the International Astronomical Union to set up a new category of body, dwarf planet, to cover Pluto, Eris, and any other distant iceball that may be found. The book is interesting not just for the search itself, but for the explicit choice that Brown faced between scientific glory and family life.
To most of the world, though, the book’s interest comes because of the demotion of Pluto. It was no longer a real planet, but a dwarf one, whatever that meant. This change turned out to be surprisingly controversial among the general public, although the astronomers largely supported it. People had a set image of what was actually in the solar system, and didn’t like the change. It prompted a new mnemonic for the names of the planets: “Mean Very Evil Men Just Shortened Up Nature”.
The classification of planet vs non-planet is pretty arbitrary, of course. Brown actually favors one with three categories: giant planets (Jupiter, Saturn, Uranus and Neptune), rocky planets (Mercury, Venus, Earth, and Mars), and planetoids (Ceres, Juno, Pluto and all of his discoveries), but that didn’t make it. If demoting Pluto was controversial, demoting the Earth would have been even more so.
More interesting was how he went about this search. It turns out that there were images of a lot of these objects already in the astronomical archives, and many could have been found with old scopes and photographic film. They hadn’t been found because:
- They moved too slowly,
- They were out of the ecliptic, unlike the known planets,
- There were too many stars to search manually using blink comparators, which is how Clyde Tombaugh had found Pluto
What Brown did was to automate the search process. He notes with some embarrassment that he knows more about programming than he does about the constellations. He started with the 48″ Schmidt telescope on Mt Palomar, which still used film, and digitized the big negatives that he got. Then he and a grad student, Chad Trujillo, wrote software to look for objects that moved against the background of fixed stars. The initial programs were terrible, and gave tens of thousands of false hits. The computer couldn’t tell moving objects apart from scratches, splotches, and simple noise. He had to go through the hits one at a time to validate them.
Here’s one of the places in the book where the cracks appear in the sunny Californian facade. The book has a steady jokey tone, but then it describes months of staring at a screen day in and day out, clicking on tiny images of stars to decide whether they’re real planetoids or not. That’s not chilling at the beach, dude. At another point he mentions how he lived in a remote cabin above Pasadena as a grad student, a place that didn’t have lights or indoor plumbing. What, really? When he finally does marry and start a family, he obsessively charts the sleeping and feeding habits of his new-born daughter, and blogs about her every day.
I lived in California for two years (albeit a long time ago), and saw this behavior a lot. The people there would be entirely friendly and pleasant, but they had these obsessive drives just below the surface. They were capable of enormous amounts of work in whatever their field was. They were different from the nerds I was familiar with because of the intensity of focus they brought to a field, masked by a outwardly casual demeanor. They cared about exactly the field they were trying to succeed in, and had no knowledge of or interest in things outside it.
So at one point in Brown’s story he becomes discouraged. By then he has been looking for the mysterious Planet X for years, and has only found the minor body Quaoar. That’s enough for tenure, but not what he wants. His star student, Trujillo, has graduated, and he was the one who wrote most of the code. He’s searched all the obvious places, and searching whole new areas of the sky looks daunting.
He goes out for coffee with one of his students, Antonin Bouchez, and lays out the whole problem for him. “I’m done,” Brown told him. “We’ve looked at enough sky and if there was anything else out there we would have seen it by now.” Antonin tells him that he’s crazy. “So how are you going to feel if you pick up a newspaper one morning and read about someone discovering something right where you didn’t look?”
Brown had just gotten engaged. He had gotten used to going home for dinner at a reasonable hour, to taking trips with his fiancé, to living a normal life. Antonin’s comment kick-started the engine of his ambition. He did go home and ask his future wife if he could geek out for the next year, and fortunately for them she said “Go find a new planet.”
He dove back into the software and found ways to quickly eliminate most of the false positives. He was working with a big new digital camera, one that was much more sensitive than the chemical film, and didn’t need developing or digitizing. He could scan far more objects far more quickly. In short order he made two more discoveries, later called Sedna and Haumea, but at the time he called the Flying Dutchman and Santa.
Here’s where a moral element comes in, as must happen in any memorable story. In 2005 he was working away on nailing down the characteristics of these bodies, delaying the announcement of the discovery until he knew their distance and size, when he received an email that someone else had found Santa. An unfamiliar group in Spain had just publicly described a body with the same orbit as Santa, and had verified it by looking at old plates. He was dismayed, of course, but gracious about it, and sent emails to the astronomer and to others congratulating him on his discovery. It’s first publication that matters in science, not first discovery.
His friend Brian Marsden at the Smithsonian Astrophysical Institute in Cambridge was skeptical, though. “Something smells fishy about this.” Brown hadn’t published anything, but just a few days before there had been a release of the titles of papers at an upcoming conference. His students were going to present their results on the bodies, and had used a code name for Santa, K40506A. There’s a database in Ohio that logs the activity of all the telescopes in the world. Right around then someone had Googled for that term and found just where a telescope in Chile that he had using was looking for that object. The IP addresses matched those of the Spanish institute. The Spaniards had looked in that part of the sky themselves, figured out Santa’s orbit, checked it against the old plates, and stole Brown’s thunder.
He didn’t find out about this for months. When he finally wrote to Spain asking what was going on, he got no reply. He persisted, and was finally told that he had been hoarding the data about Santa, and that someone had to release this to the world so that it could be widely examined.
Well, that was annoying. Brown knew that he had some enemies because people on a Usenet group had been attacking him over the delay in announcing Quaoar. One of those people, a German amateur astronomer, was cited in the Spanish paper. They went wild over Santa, to the point where Brown couldn’t read the group any more for the sake of his blood pressure. He did write a nasty-gram to the head of the Spanish institute, but never says what became of his rival.
It didn’t really matter. By then he had found a genuinely large body, Eris, and his reputation was assured. He had to announce things sooner than he would have liked, but the data was solid anyway. The Wikipedia page on Santa/Haumea, is rather neutral on the controversy. He did wait more than a year for the announcement, but upstaging him by Googling his telescope positions really was unconscionable.
So his story has a happy ending. He really did find something extraordinary. His fiancé didn’t leave him when he abandoned her for his quest. His daughter sounds adorable (everyone gives her Pluto the dog presents). He made full professor in just six years. Maybe obsessiveness isn’t so bad after all.