The Lowell Observatory in Flagstaff, AZ

Slipher Rotunda Museum

On Monday, we opted for a low key day after all the hiking yesterday, and headed for the Lowell Observatory, established in 1894, on Mars Hill in Flagstaff. Our tour began with a short film on the history of the Lowell Observatory and a bit about its founder, Percival Lowell. Our friendly tour guide, Marie, took us on a tour of the Clark Telescope, built to specification for Mr. Lowell in 1896 to search for evidence of life on Mars. After seeing 'canals' on the surface of Mars, Mr. Lowell assumed these were man-made channels for farming purposes made by Martians. He drew extensive drawings of the planet using the images he saw through the Clark telescope.

The telescope is housed in a large wooden dome built by a pair of brothers, Godfrey and Stanley Sykes, who were bicycle repairmen from England. The dome's top portion actually rotates on wheels inside the structure at the push of a button. The original metal wheels were replaced at some point by old Ford truck tires, complete with old rims. Very charming. Marie introduced us to the telescope and mentioned that it is a refracting telescope with a 24" lens.

Slipher Rotunda Museum

From the Clark Dome, she led us to the Slipher Rotunda Museum where the Pluto Tour began. The discovery of Pluto in 1930 occurred only after the calculations of the wobble in Neptune's orbit by Percival Lowell. After his untimely death at age 61 in 1916, the search for Planet X stalled until Clyde Tombaugh was hired in 1928 to continue the research.

Pluto Telescope

In 1930, after an extraordinary amount of dedication, patience and detail, Mr. Tombaugh found Pluto. Using an astrograph (telescope only used to take photographs), he compared two photographs taken 5 days apart on glass plates and then looked for the differences between them with a blink comparator (a lightbox with an eyepiece to view one plate then the other in rapid succession). Each photograph had the same 10,000 pinpricks of light with only one extremely small difference, Planet X. What an excruciating attention to detail he had in order to find Pluto. With this accomplishment, Mr. Tombaugh went on to have many more successes in astronomy. Marie showed us the telescope used for Mr. Tombaugh's search for Planet X, a reflecting telescope, meaning that it employs mirrors instead of lenses. A reflecting telescope can be made with a shorter barrel than a refracting telescope, but can actually be much more powerful since the mirrors can be made very large and supported from behind. Lenses over 40" in diameter tend to sag under their own weight, causing distortion.

Pluto Telescope Dome

The Lowell Observatory is also famous for being the site where Vesto Slipher discovered the first evidence of the expanding universe in 1912. Using the Clark Telescope and a spectograph, he saw the spectrum of Andromeda change, showing the galaxy rushing toward us at an incredible speed. His impact on astronomy and especially on Lowell Observatory, was remarkable. Mr. Slipher was responsible for hiring Clyde Tombaugh as well overseeing his work on Pluto, and he served as director of the Observatory for 26 years until 1952.

Percival Lowell pointing
the way to the Pluto Walk

A wood carving of Percival Lowell points visitors to the Pluto Walk, an outdoor path where the solar system is scaled down to 350 feet. At the end of the walk, a sign indicated that were we to continue to the next closest star at the same scale, we would need to walk 464 more miles, illustrating just how empty space really is.

After the tours, Marie treated us to a view of the sun through the solar telescope where we saw sun flares and prominences. She also mentioned the night viewing program at the Observatory where we could come and see the moon and such through the big telescopes.

We left the Observatory and headed to lunch at Pato Thai in the historic downtown. It was a great meal with plenty to eat for a low price. Hard to beat that. After lunch, we did some shopping and then returned to the RV for dinner and to wait until the night viewing program began.

Clark Telescope

We returned to the Observatory at about 7pm, where we first watched a film about the birth of stars, the planets of our solar system, the observable universe, the formation of nebulae and lots of other interesting topics. Outside, we found three astronomers chatting with folks. One astronomer had a small telescope trained on the moon, where we could see the half moon and several craters. A slight haze made the image a little fuzzy, but it was still impressive. We next headed up to the Clark Dome to see the moon through the giant 118 year old Clark telescope. The first time we looked through it the moon was obscured by quite a bit of haze, but the second time we were floored with the details we could see. What a spectacular sight! The astronomer mentioned that we were looking at the crater Copernicus just outside of the shadowed part of the moon's face. Wow...that was fascinating.

Next we looked through an eight foot tall telescope out in front of the Rotunda Museum, where the astronomer had it aimed at Venus. The little planet looked like an extremely bright, but very tiny, sliver of the moon. It was actually hard to watch it for very long because it was so bright through the telescope. Next, he trained the telescope on Mizar, the middle star of the three stars that form the handle of the Big Dipper. Mizar is a binary star, meaning it is actually two stars that are gravitationally bound to each other. We could easily see that it was two stars through the telescope...how cool! After that, he moved it to show us Mars, near the bright Moon. Mars looked like a slightly reddish dot, but we were still impressed.

Clark Telescope

Later on, once the haze cleared a bit more, the Clark telescope was moved so that we could see Saturn through it. What an experience. Saturn appeared as only a tiny pea-sized bright white dot, but we could easily see its rings and three of its many, many moons. Titan (actually larger than the planet Mercury), Rhea and Dione appeared as only little pin pricks of light, but we were totally enchanted with them.

Reluctantly we left the Observatory, but we were smiling ear to ear all the way back to the RV from the fun of playing amateur astronomers.