old equipment

Yesterday we got the first surface resolution of Charon, Pluto’s largest (and first discovered) moon. Pluto and Charon

(Thanks as always to the excellent io9.com for this composite picture.)

Charon wasn’t discovered until 1978 — almost fifty years after Clyde Tombaugh first spotted Pluto’s infinitesimal speck on those big glass plates he’d exposed during hour-long sessions at the 13-inch telescope atop Mars Hill.  Here’s the Zeiss Blink Comparator he used to compare one plate with another.  (Formerly housed in the beautiful Saturn Dome room at Lowell Observatory, the comparator has now been moved to the Smithsonian Institution.)

It’s hard to convey exactly how tiny the speck of Pluto is on those plates — but boy, is it tiny.  So small, in fact, that Pluto could easily have gone undiscovered for decades.  Only a man like Clyde Tombaugh — diligent, devoted, impossibly obsessive — could have found it.  Read more about Clyde’s homemade telescope here, and more about Clyde generally here.

And if you’re so inclined, you can check out my novel about Clyde Tombaugh and the discovery of Pluto here.  Order one here today!  (End of commercial.)

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.

What is it about the demotion of Pluto that’s fired so many imaginations?  What did we lose when that outermost place was taken from us?  And what is that signal that’s being sent back through those headphones?  Check it out here

And lo, the Plutovian armies gather.