The Union Recorder

August 13, 2013

OUR SPACE: Mt. Wilson: Still cutting edge after all these years

Beate Czogalla
The Union-Recorder

MILLEDGEVILLE — These days every school kid knows that our solar system is just one of many — a quite unremarkable bunch of planets around an ordinary main sequence star, somewhere out there in the suburbs of the galaxy. But not too long ago people thought we were at the center of the galaxy (and doesn’t that sound familiar — before then we thought we were the center of not only the solar system but the entire universe). Generations of people hold things as infallible truths, until scientific evidence proves them wrong.

Mt. Wilson Observatory is one of those big game changers. During the first half of the 20th century it was the work place of famous astronomers such as Edwin Hubble (yep, that big space telescope is named after him) and George Ellery Hale, who was instrumental in establishing the then-new science of Astrophysics, which deals with the actual physical processes inside stars.

Although the proximity to Los Angeles and ensuing light pollution have forced much of terrestrial optical astronomy to remote places like the high mountains of Chile, Mt. Wilson still has much sought-after qualities that allows it to compete with even the most modern of observatories.

Astronomers call it “see.” A place with good “see” will have calm, stable air which allows for observations with minimal optical distortion. You can experience the phenomenon on any hot day looking across a parking lot, when the warm air distorts your vision and makes distant vistas flicker  and move.

Hale facilitated the construction of the large 60-inch diameter Hale Telescope in 1908, which was the largest in the world until the construction of the 100-inch diameter Hooker Telescope in 1917 — also by Hale on top of Mt. Wilson. It remained the largest optical telescope on Earth until the 200 inch telescope at Mt. Palomar became operational in 1948.

Nowadays you can rent the 60 inch telescope for the night, and soon you’ll also be able to throw your own star party with the 100 inch telescope. But there’s a whole lot more to Mt. Wilson yet. The site is also home to several solar telescopes, including one that sits atop a 150 foot tall tower. At its base an image of the sun is projected onto a large sheet of paper, and despite all the computerized equipment attached to the telescope drawings of sunspots are still made daily by hand with a No. 2 pencil — a proud tradition going all the way back to the first images produced. It feels a little bit like an old submarine in there — the smell of machine oil, the humming of computers — and a bust of Edwin Hubble perched atop a red tool box.

The 100 inch telescope simply boggles the mind. It’s hard to compare it to anything — this giant structure inside the vast empty dome of the cupola where it is housed. Standing directly beneath the enormous instrument you can clearly see the glass foundation that bears the reflective surface of the high precision mirror.

But it doesn’t end there. The State of Georgia has a very special connection to Mt. Wilson, since Georgia State University operates the CHARA Array — a series of six smaller telescopes arranged in a Y-shaped formation. All six telescopes focus on the same celestial object; the light collected passes through long vacuum tubes to a central processing facility where huge beam adjusters working at the micrometer range adjust the 6 beams of light into a single image and compare the minute deviations in a process called optical interferometry. It’s about as cutting edge as it gets, and the ingenious method of observing distant stars will keep Mt. Wilson at the forefront of astrophysical science for many more years to come.

Read up on Mt. Wilson at

Beate Czogalla is the Professor of Theater Design in the Department of Theatre and Dance at Georgia College & State University. She has had a lifelong interest in space exploration and has been a Solar System Ambassador for the Jet Propulsion Laboratory/ NASA for many years. She can be reached at