February 2010

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.


Patsy Edson wasn’t (as my novel would spuriously have it) a nurse in Flagstaff, Arizona.  In truth the couple met at the University of Kansas, and were married in 1934.  Clyde was 28. 

The Tombaughs remained married until Clyde’s death, at 90, in 1997.

Galileo was the first to see Neptune, making a note of it in 1613 — but because it appeared nearly stationary in the sky, he didn’t recognize it as a planet.  It would be another 233 years before Johann Gottleib Galle rediscovered Neptune, directed by calculations made by Urbain Le Verrier, who had observed irregularities in Uranus’ orbit that could best be accounted for by the existence of another, undiscovered body beyond that planet’s orbit.   Galle’s discovery of Neptune in 1846 — less than a degree from the position suggested by Le Verrier’s calculations — would have a profound influence on the search for Planet X some decades later. 

The great strangeness of the discovery of Pluto is this: Percival Lowell’s calculations of the irregularities in Uranus’ orbit suggested that a roughly Neptune-sized planet remained to be discovered at the edge of the solar system, beyond Neptune itself (a “Trans-Neptunian Object”).  And in 1930, Pluto was indeed discovered very close to the position Lowell predicted for it.

But Pluto is far too small to have introduced any significant wobble into any object’s orbit.  So why did Lowell’s math send him right to Pluto’s position?

As it turns out, Pluto’s location was nothing but an amazing, impossible coincidence.   Still, it’s hard not to imagine some kind of mystical explanation, as though Lowell had managed to divine some truth about the Solar System simply by sitting in the high desert air for decades.

And as it happens, there aren’t any significant wobbles in Uranus’ orbit; the observations Lowell was using were minutely faulty.

Well, it is a mystery.

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.

Pluto is about 9 light hours from Earth.  The newest planet to be discovered is about 480 light years away.  CoRoT-7b (cool name!) is relatively small as exo-planets go, with a radius only about twice that of Earth.   But there’s no life there — almost certainly — because CoRoT-7b is only 1.6 million miles from its sun, meaning the planet’s sunward surface could be around 4,000 degrees Fahrenheit.  (We’re parked at a comfy 93 million miles from our sun.)

Because its orbit is so small, a “year” on CoRoT-7b lasts only 20 hours.

Here’s what it might look like.  And you can read more about it here.