Clyde Tombaugh

Hence the pizza!  Nice of the NY Times Op-Ed page to allow me a little room to celebrate what would have been Clyde Tombaugh’s 105th birthday.

A blogger at the Philadelphia Area Center for History of Science has been writing about the Planet X story lately; in his most recent post, Darin points out that in the initial announcement in 1930, V.M. Slipher went out of his way to credit Percival Lowell for leading the way to the planet’s ultimate discovery — while underplaying Clyde Tombaugh’s central role in the painstaking photographic search.

The extension of credit to Lowell, and the relative under-recognition of Tombaugh, could suggest that Slipher simply knew where his bread was buttered.  You give credit to the man with his name on the letterhead, after all, not the undereducated farmboy from Kansas.  And part of the mission of Lowell Observatory was to rehabilitate the reputation of its founder, who was thought to be a bit of a kook.

(For example, Lowell had believed passionately in the existence of a Martian civilization — sustained by an elaborate series of canals.)

It’s worth noting that Slipher’s relationship to Lowell — and the Lowell family — was (understandably) a complicated one. By 1930, Slipher’s old friend Lowell had been dead for fourteen years. Constance, Percival’s widow, had been a thorn in Slipher’s side since the astronomer’s death, spending more than a decade fighting Lowell’s multimillion-dollar bequest to his own Observatory and cutting the astronomers’ salaries in the bargain. On the other hand, once the Planet X project got underway again in 1928, the Lowell family (apart from Constance) invested substantially in the equipment needed, including the remarkable triplet lens the 13-inch astrograph required. It can be imagined that the family expected results from their investment, and that Slipher’s emphasis of Lowell’s role in the discovery of Planet X was indeed at once an acknowledgment of his old friend’s ancient, originating ambition and a recognition of the family’s more recent, crucial involvement.

But consider another line as well. Slipher — and others involved in the Planet X search — knew they had an unusual case in Pluto.  Even before announcing their discovery to the world, they had tipped to the notion that Lowell’s calculations had not in fact been borne out by the discovery of Planet X, because it was too small to have been detected mathematically.  Still, one can imagine Slipher and the others being reluctant to get in the way of a good news story.  We don’t know who wrote “confirmed” here in the headline, but I bet Slipher didn’t protest too much.

Note that this question should be distinguished from the matter of whether Planet X should have been called a “planet” to begin with.  What other word would have fit?  Though its exact dimensions weren’t clear, it was still thought to be a fairly large object.  Certainly it was no asteroid.

The Tombaughs were farmers of wheat and oats; together with other farmers in Pawnee County, they were part owners of a great steam tractor and thresher, like the one here below (I couldn’t find a picture of the Tombaughs farming).  Clyde Tombaugh was responsible for some of the maintenance on the thresher, and some of the same equipment he used for grinding his lenses he also employed in the sharpening of the thresher’s many blades.  The meticulous, umcomplaining work he did around the farm would surely be of help to him later, when he was poring over the endless photographs of the night sky, looking for the one moving speck that would be Planet X.


The steam tractor provides the power for the great whirring thresher belts while you rake the cut wheat and gather it into your arms and throw it into the thesher mouth, to be separated grain from chaff.  After an hour of standing beside the roaring machines, gathering the cut wheat into your arms, bending and standing, raking and kneeling, you stop hearing the engine, you stop thinking of hearing as something you do, and then all at once the noise emerges again into your consciousness, full of its many constituent parts, a rumble and a liquid pounding and a million high whinnying sounds from the belts and other things besides.  You feel it in your sternum in a strangely personal way.

A fascinating post here braiding together the lives of Clyde Tombaugh, Venetia Burney, and the unusually named Plato Chan.  Born on March 14, 1930, he was supposed to be named Pluto, as it happens — and he would come to his own early fame, as Peter Sieruta points out.  Influences and perturbations indeed!

Plato (Pluto) Chan, winner of the Caldecott at age 12

It’s hard to believe, but Clyde Tombaugh really did make his own telescope essentially from scratch.  In an effort to try to understand how this was actually done, I hunted down old reference guides that would make the process plain.  These images are from 1001 Celestial Wonders, published in 1931.  For a complete account of the step-by-step procedure, and for a description of the materials Clyde might have made use of, go here.

Somehow, when you grind two glass blanks against one another, one goes convex and the other goes concave.  I honestly don’t entirely understand this myself, even after reading about it extensively.  But it works.

In the novel, Clyde does a fair amount of this work, especially early on, as he’s making the telescope that will get him, eventually, to Flagstaff and Lowell Observatory.

Clyde’s grinding post must have looked very much like this.  In the stained glass window rendering here, you can see all these elements.

In the archives of Lowell Observatory, under the excellent guidance of archivist Antoinette Beiser, I came across this typewritten memo – in its original, a few pages long.  While it’s not clear who composed this note, someone has penciled “VM?” in the upper margin — Vesto M. Slipher, director of the Observatory.

In this memo, Slipher (probably) is acknowledging that there was some delay in the announcement of the discovery of Planet X (later Pluto).  Clyde Tombaugh found the retrograding trans-Neptunian object on February 18, 1930.  Lowell Observatory didn’t announce their findings until March 13.  This happened to be Percival Lowell’s birthday — as well as, through one of this story’s many cosmically-arranged coincidences, the date on which Uranus was first discovered.

Aside from the pleasing timing, why the delay?

As I’ve written here before, the astronomers at Lowell weren’t sure what they had.  The object was too small to be the gas giant they’d been expecting.  But their mathematics seemed to indicate that a gas giant was indeed what was out there to discover; only a very large planet could perturb the orbits of Uranus and Neptune in the way that was posited.  So they were understandably puzzled to have found a very small object in just the place that Lowell’s mathematics suggested a gas giant would be.

But what’s of interest to me in this memo is the phrase “In view of the unusual character of the discovery into which the institition [sic] and its founder had given so much in the way of effort and time we had to be content to allow the momentary gusts of emotion to blow over…”

One way of reading this goes: we’d been looking for the thing for so long, and under such pressure to find something, that we wanted to make sure we had something genuine before we said anything.

That’s a legitimate reason to hesitate, of course.

But I think, too, that it’s fair to read those three weeks as a pregnant pause, during which the astronomers decided whether to call this object Planet X or not — that is, whether the accumulated pressures of history and institutional expectation outweighed the obvious problems with the object.  It wasn’t what they were expecting.

So – should they gamble?  Should they go ahead and try to call this object Planet X?

Had it been a gas giant — had they found what they’d been expecting — I bet they would have announced it the next morning.  Instead, over the next three weeks, they took countless photographs of the object, hoping to solve their conundrum.  They never did.  And in the end, of course, they didn’t call it Planet X when they finally announced it.  They just called it a “solar system object apparently trans-Neptunian.”  It was the press that called it Planet X, and so a planet was born.

According to what I can find, the astronomer Kenneth Newman arrived at Lowell Observatory shortly after the discovery of Planet X in 1930.  At any rate, he begins to publish articles and to appear in Observatory photographs around 1932.  It’s nice to think of Clyde having someone to work closely with — someone around his own age, I mean.  And it’s a little eerie to see Newman here in this photograph, seemingly playing the part that the fictional character Alan Barber does in Percival’s Planet.

It strikes me that astronomy in that era — with its long periods of nocturnal solitude — could be awfully lonely labor; I imagine Clyde found it a relief to have somebody else around.

This past weekend I had the opportunity to visit Lowell Observatory again – this time to shoot some footage for what’s known these days as a “book trailer” — your basic movie trailer but — yes — for a book. Antoinette Beiser and Kevin Schindler were our guides through the old spaces and, once again, offered not only their customary spectacular hospitality but a number of useful historical pointers. Kevin Strehlow of Phoenix played Clyde Tombaugh; Travis Marsala of NAU’s theater program filled the role of the fictional character Alan Barber.  Stay tuned for the final cut!

We even managed to (sort of) reproduce the book cover inside the Pluto dome – thanks to the estimable Chris Crockett for the loan of the excellent hat!

And here’s yours truly – getting some audio from the comparator.  (Click.  Click.  Click.  Click.)

Clyde here at least gets equal billing with Percival Lowell. Notice that in June 1930 astronomers are still puzzling out Pluto’s size. They’re getting closer — rather than being 1200 times the size of Earth, now it’s “judged to be the same size as earth.”  (Today we know its mean radius to be 0.18 of Earth.)  Estimates of Pluto’s size decreased over the course of the 20th century; in 1976, astronomers determined that Pluto’s surface featured methane ice, which meant that the planet’s albedo was higher than had been theretofore suspected — which, in turn, meant the planet was smaller than it appeared.

The discovery of Pluto’s moon, Charon, in 1978, allowed for very accurate measurements of Pluto’s mass — now determined to be about 0.2% of Earth’s.

Here’s the larger version of that iconic picture of Lowell at his 24″ Clark.  Notice the handsome chair.  As his descendents say, “Percy brought a lot of Yankee with him to Flagstaff.”

If you visit Lowell Observatory you can see this telescope still in operation — in fact, you can look through it!  Check out Lowell’s visiting hours and directions here.

Trans-Neptunian Objects isn’t a term used much any longer. “Dwarf planets” is the preferred term, if you’re being PC. (“Little planets”, if you’re being really PC.)

Anyway, these are the biggies. They’re all out beyond Neptune’s orbit. They’re all large enough to be kinda planetlike in some ways — they’re in hydrostatic equilibrium (meaning they get mostly round and stay mostly round).  They’re not themselves satellites.  But they aren’t large enough to have “cleared their neighboring region of planetesimals,” i.e., to have slurped up all other orbiting bodies unto themselves.  Which means, according to the International Astronomical Union’s Resolution 5A of 2006, they aren’t planets.

And what would Clyde Tombaugh have thought? My impression of Clyde in his later life is of a man at peace with himself.  Every picture I’ve seen of him shows him beaming, and surely he was much beloved.  Though he defended Pluto’s planetary status when it first was questioned in the 1990s, I believe he also recognized his discovery of Pluto as being something of a happy accident.  And today, I can imagine him arguing that we welcome the planetary status of such substantial bodies as Eris, Haumea, Makemake, Orcus, Quaoar, and so on.  The universe had made room for him in such an unlikely fashion, after all – I believe he’d have wanted us to return the favor.  So on Clyde’s behalf, let the IAU know we want Pluto back!

(Thanks once again to the great Laurel Kornfeld for her ongoing, informed contributions to this discussion – and for filling in some details on the IAU kerfuffle.)

Clyde Tombaugh boarded the train to Flagstaff in January 1929.  He’d been invited by Vesto Slipher for a trial period – nobody in Flagstaff knew much about Tombaugh beyond the fact that he’d made his own telescope and was in need of work.  He came cheap, anyway — he had only a high school degree.

Clyde could indeed (as I have it in Percival’s Planet) have been carrying with him the new Popular Science Monthly, which featured articles on the “world’s greatest telescope,” the “marvels of the newest electric ocean liner”,  and, for the auto buffs, “Reverse Pliers Serve as Handy Valve Lifters.”  Clyde’s train left Larned, Kansas, on January 14, 1929 – the day after another Arizona legend, Wyatt Earp, died in a Los Angeles bungalow at the age of eighty, of chronic cystitis.  (Whatever that is.)

Clyde was nervous, of course, not knowing what to expect in Flagstaff; and well he might have been.  His future was in no way certain in Arizona.  On February 7, 1929, three weeks after Tombaugh arrived, Vesto Slipher wrote (to Lowell Observatory trustee Roger Putnam, in Massachusetts):

Mr. Tombaugh, the young man from Kansas, has been here since about the middle of January.  We think he is going to develop into a useful man.  He has several good qualities that are going to make up we think for his meager training.  He is looking forward to the arrival of the new objective and is eager to be working with it.  He has good attitude; careful with apparatus, willing to do anything to make himself useful and is enthusiastic about learning and wants to do observing.  We believe these qualities will after a time largely overcome his deficiency of schooling and training.

Slipher is not terribly impressed, perhaps.  But Clyde costs him only $90 a month, and he is awfully dogged.  So Slipher lets him stay.

Such a close thing life is, at every turn.

I found writing a historical novel very, very hard.  Like, hard. Hard to keep my narrative eye in the moment; I always felt I was lifting my gaze from the scene in front of me, writing it from a position of privilege — the future, where everything had already happened.  Month after month, I struggled to make the events of this book feel as though they were really happening — anywhere, at any time.

I had been writing in the past tense.  Finally, in desperation, I decided to try the present tense.  This is the first section I wrote in the present — Clyde Tombaugh, driving into Burdett to pick up supplies for his homemade telescope in 1928:

I found it worked — I could know only what my characters knew, at the moment they knew it.  It worked, for whatever reason.

In the selection above, the material in red made it into the book.  Everything in black got cut.  And the phrases in blue were added sometime later.

The more you write, the more  you have to work with.  It’s always easier to cut than to add!

Research is a seduction.  It’s not writing, for one thing, so it produces the illusion of work without the strain.  But it has such pleasures to offer – the mysterious immediacy of old charts, with their hidden stories; the sweet smell of elderly paper; the glorious cracking of glue; the silence of a library table, where no one knows what you’re up to.

They were a cautious bunch, V.M. Slipher especially.  Years of association with Percival Lowell’s brand of lunacy can leave you a little gun-shy.

But the “object” they’ve found is “one apparently fulfilling Lowell’s theoretical findings”.  In other words, this strange, tiny body is just where it’s supposed to be — going by Percival Lowell’s decades of residual calculations.  And it’s definitely “trans-Neptunian” — that is, it’s out past Neptune, and it’s retrograding.  And the only thing that retrogrades is something in orbit around the sun.

So what is it, if not a planet?

Well, you’ve got to possess a certain kind of character to have an elementary school named after you.  To wit: Clyde Tombaugh Elementary in Las Cruces, New Mexico.

Go Comets!

I read from Percival’s Planet for the first time last week at Chatham University in Pittsburgh, and I had the very good luck to have Jan Littrell of Chatham in attendance.  Her husband Tom Hogan is a Tombaugh buff — and happened to have not one but TWO IDENTICAL autographed Clyde Tombaugh posters at home.  And — this being Pittsburgh — Tom just went and handed one over to me.

There it is — Clyde’s perfect signature, bottom left.  Bonus signature: J.W. Christy, discoverer of Charon, Pluto’s largest moon. 

Thanks, Tom and Jan!  

It was a February afternoon in Flagstaff; snow was falling beyond the big window of the Administration Building.  Clyde Tombaugh had been blinking plates for ten months — hour after hour of painstaking examination of giant, high-resolution photographic negatives.   The comparator was giving off its relentless clack-clack-clack, swapping one plate for its twin, over and over, and Clyde, with the determination only a farmboy could bring, was staring through the brass eyepiece.

And then he saw it – a minute flickering.  One tiny black speck danced before his eyes. 

 He was very well suited to search for Planet X.  But now he had found something.

He turned off the comparator — reaching around beneath, as though feeling under its skirts — then went across the hall, where Carl Lampland, one of Lowell Observatory’s astronomers, was working.

“I’ve found your Planet X,” Clyde said.

It’s fair to say Clyde had at least a healthy interest in the possibility of life on other planets, and he’s on record as having witnessed a few things that puzzled him.  Some of his explanations have to strike us as pretty half-baked — for example, in 1949, he suggested that a bright flash he observed on the Martian surface in 1941 might have been an atomic blast.  The following account of a possible UFO sighting — submitted by Clyde in 1957 — displays his usual meticulous observational eye.   What this guy saw, he really saw — whatever it was.

“I saw the object about eleven o’clock one night in August, 1949, from the backyard of my home in Las Cruces, New Mexico. I happened to be looking at zenith, admiring the beautiful transparent sky of stars, when I suddenly spied a geometrical group of faint bluish-green rectangles of light similar to the “Lubbock lights”. My wife and her mother were sitting in the yard with me and they saw them also. The group moved south-southeasterly, the individual rectangles became foreshortened, their space of formation smaller, (at first about one degree across) and their intensity duller, fading from view at about 35 degrees above the horizon.

“Total time of visibility was about three seconds. I was too flabbergasted to count the number of rectangles of light, or to note some other features I wondered about later. There was no sound. I have done thousands of hours of night sky watching, but never saw a sight as strange as this. The rectangles of light were of low luminosity; had there been a full moon in the sky, I am sure they would not have been visible.”

UFO enthusiasts count Tombaugh as one of their own.

Here’s a bit about the Lubbock Lights.

Thanks due to Antoinette Beiser, Kevin Schindler, Travis Marsala as Alan Barber, Kevin Strehlow as Clyde Tombaugh, and Chris Crockett (for his cameo as Vesto Slipher!) — and of course to the fine crew of Nobun Productions, without whom this book trailer etc etc.

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