The Basics

• The 200-inch telescope was conceived and planned by George Ellery Hale, an astronomer and visionary who made possible four successive telescopes that were the world’s largest: the 40-inch refractor at Yerkes, the 60-inch and 100-inch reflector at Mount Wilson, and the 200-inch at Palomar that now bears his name.

• Plans for the telescope began in 1928 after $6 million in funding was secured through the Rockefeller Foundation.  The glass blank for the mirror was created by the Corning Glass Works out of a then-new material called “Pyrex”.  Grinding, figuring, and polishing of the mirrors removed 5 tons of glass and took 13 years, including a 4-year gap caused by World War II.

• The telescope was opened in mid-1948 at a meeting attended by dignitaries from all over the world.  Some took a slow spin on the telescope’s massive dome.  Edwin Hubble himself took the first image with the 200-inch in January 1949.

• After an prodigious but exhausting career, Hale died in 1938 and never saw the completion of his greatest work.

The Dome of the 200-inch Hale Telescope on Palomar Mountain

A Deeper Look

• The telescope is a Cassegrain with aperture of 5.1 meters, figured at a focal ratio of f/3.3.  Until recently, astronomers actually sat in a cage at the prime focus of the big mirror at the top of the telescope and stayed there all night to take images and spectra.  Today, most observations are done at the Cassegrain focus at the bottom of the tube with electronic equipment so the astronomers stay warm in the control room.

• The 200-inch was the largest telescope in the world from 1949 until 1976, when a 6-meter Russian telescope was commissioned.  But the 6-meter had significant problems with its optics, and never had the utility or cachet of the Hale, which was not surpassed in resolving power until the 10-meter Keck I telescope came online in 1993.

• While now dwarfed by larger telescopes such as the Keck, Gemini, and Subaru, the 200-inch is still a workhorse of astronomy.  Caltech, which runs the observatory, gets 1/2 the observing time, while Cornell University and the Jet Propulsion Lab get 1/4 each.

• The telescope has been updated with adaptive optics to cancel out the turbulent effects of the atmosphere.  The “Big Eye”, as it was called when it was finished, is still used for astronomical research some 290 clear nights each year.

Good To Know

The word Palomar means “pigeon house” in the language of the La Jolla indians.  While many call the mountain “Mount Palomar”, the location’s proper name is “Palomar Mountain”.  The mountain also houses a 60-inch reflector, the famous 48-inch Schmidt Camera used for the Palomar Sky Survey, and an 18-inch Schmidt Camera.

Personal View

It was a treat to see the 200-inch up close during a recent pilgrimage to the observatory on a cold snowy day in late March (snow seems to follow me everywhere).  While I knew the specifications of the telescope, I was struck by its immensity.  Sure, it’s far from the biggest telescope in the world.  But it’s still a massive machine… the truss tube is 60-feet long and weighs 70 tons.  Yet it’s so well balanced and engineered that a 1/10 horsepower motor can move the whole thing.

This telescope and the astronomers who used it made huge advances in understanding the structure and size of the universe, and it did me good to stand in its presence.  You can see the Hale telescope for yourself at the Palomar webcam.

The Basics

• Parsons was a wealthy man, and held a peerage as the 3rd Earl of Rosse in Ireland. He was trained in mathematics and had a fascination with astronomy. To build his gigantic telescope, he invented many new techniques for construction, as did William Herschel decades before.

• Built in only two years, the 72-inch telescope was mounted between two massive stones walls for support. It could only aim at objects near the meridian… the line in the sky from north to south. Still, this telescope was considered a marvelous achievement, and gained fame within the British Commonwealth.

• The mirror of the telescope was made of speculum, an alloy of copper and tin. It tarnished quickly and required re-polishing every 6 months. A second mirror was kept on hand as a replacement during polishing sessions.

A Deeper Look

• Despite frequent clouds in the blustery Irish skies, Lord Rosse was among the first to see the spiral structure of galaxies with his massive telescope.

• He was also fascinated with diffuse nebula and postulated that all nebula were simply composed of unresolved stars. Rosse strongly opposed the idea that nebula were made of gas from which stars and planets evolved. He was incorrect, of course. Not until the 20th century was it proved that nebula were made of glowing gas which eventually coalesced into stars.

• After Rosse’s death in 1867, the telescope fell into disrepair and was disassembled in 1914.

• Today at the same site in Parsontown, Ireland (now called Birr), a replica of the telescope stands as a tourist attraction at Birr Castle, Rosse’s ancestral home. But you can’t look through it for reasons of personal safety.

A sketch of the 72-inch scope at Parsonstown (now Birr, Ireland)

A Bit of History

Three years after the Leviathan of Parsonstown was disassembled in 1914, another 72-inch telescope was put into service at what’s now the Herzberg Institute for Astrophysics near Victoria, British Columbia. Unlike Rosse’s telescope, the Canadian instrument was made with modern optics, mounting technology, and a dome-shaped housing. The Plaskett telescope, as it was named, was the largest telescope in the world for a few short months until the 100-inch reflector at Mount Wilson in California saw first light. The Plaskett telescope is still used today.

Personal View

Complain as I might about my own rainy clime, many of the stunning achievements of early European astronomy were based on observations from cloud-plagued countries like England, Ireland, Scotland, France, Denmark, and Germany. But the ingredients for great discovery were there: curiosity, a keen mind, a good telescope, and endless patience.

The Basics

• The Adler is the only museum in the world with two full-size planetarium theaters. The dome of the historic Sky Theater is visible from the exterior of the building. A classic Zeiss planetarium projector displays an accurate depiction of the night sky onto the inside of the dome.

• Feature video presentations are given using Digistar 3 simulator technology in the Star Rider theater, built in 1999.

• “The Solar System” is a favorite exhibit which explores planets, moons, comets and asteroids. You can drive a rover to examine the simulated surface of Mars, shoot projectiles into a soft surface to make your own craters, and sit down at a computer to create your own solar system and test its gravitational stability.

The dome of the Adler Planetarium on Lake Michigan

A Deeper Look

• The Milky Way Galaxy exhibition gives you a 3D tour of our dynamic and evolving galaxy.

• A new permanent exhibition reveals past highlights of space exploration, as well as current plans to return to the Moon later this century. This exhibition features the fully-restored Gemini 12 spacecraft, which flew in 1966.

Good To Know

The founder of the planetarium Max Adler, had a keen interest in antique astronomical artifacts. He purchased a collection of about 500 astronomical, navigational, and mathematical instruments from the 12th to 20th centuries. Many are on exhibit at the planetarium. This fascinating display is one of the largest of its kind in the world.

Personal View

I last visited Adler on an icy day in early 2007. There was much to see, but the exhibit I remember most is the set handwritten letters by Jim Lovell, commander of Gemini 12 and the “successfully failed” Apollo 13 mission. As a young boy in the 1940′s, Lovell developed an interest in space travel and wrote letters to esteemed scientists to ask how he might one day go into space. His subsequent career as a naval officer, test pilot, and celebrated astronaut are testament to his vision, determination, and the extraordinary times in which he lived.

The Basics

• Yerkes Observatory was opened in 1897 as part of the newly-minted University of Chicago, a first-class university opened in 1892 and funded by John D. Rockefeller.

• George Ellery Hale conceived the idea of a giant refractor in 1892. Hale by chance overheard the famed lens-maker Alvin Clark declare that two optically perfect 40-inch glass disks were available for polishing into a lens. Hale himself was just hired at the University, and lived just a short distance away in Hyde Park in south Chicago.

• The telescope was financed by industrialist Charles T. Yerkes, whom Hale enticed with the promise of eternal fame as the namesake of the largest refracting telescope in the world.

• This first great age of astronomy, and of much of science, was financed by donations from the legendary businessmen of the day like Yerkes, Rockefeller, Andrew Carnegie, and James Lick.

Aerial photo of Yerkes Observatory

A Deeper Look

• Lake Geneva presented the best combination of clear, steady skies and proximity to the University. The site selection committee said, “The site is high and beautifully located, the atmosphere is clear, without danger from the encroachment of manufactories, railroads, or electric lights.”

•The telescope tube and mount were displayed at the world expo in Chicago, although they were nearly destroyed during a fire in late 1893.

•Because a glass lens sags under the force of gravity and loses its carefully configured shape, no one has yet built a refractor with a lens larger than the 40″ at Yerkes.

A Bit of History

The observatory was finally dedicated on Oct. 21, 1897, with a gala celebration that included university trustees as well visiting astronomers and physicists from around the world. The collection of astronomers at the dedication in 1897 formed the seed of what is now the American Astronomical Society.

Personal View

Palomar, Lick, and Yerkes… these are my favorite of the “classic” observatories. I’ve visited Lick and Yerkes this year… Palomar is not far behind. I make these sacrifices, dear reader, to present you with the wonders of these altars to astronomy.

Postscript

Much of the pristine forest surrounding Yerkes will be turned into a resort, though the observatory will remain a centre for astronomy education and outreach. As author Conrad Aiken said, “All things lovely will have an ending.”

The Basics

• Shortly before his death in 1876, James Lick, an eccentric businessman and one of the state’s wealthiest citizens, designated a portion of his estate for the construction of a telescope “superior to and more powerful” than any yet made.

• Lick’s gift led to the construction of the 36-inch (91.44-cm) refracting telescope on Mt. Hamilton. This scope, built by Alvin Clark and still in use today, was the world’s largest telescope from January 3, 1888, until the opening of Yerkes in 1897. It remains the second largest refractor in the world.

• The dome for the 36” refractor was engineered by ship-builders. Today, you can see markings on the inside of the dome that reveal the naval origins of some of the materials.

A Deeper Look

• The location of Lick on Mt. Hamilton provides calm air and excellent viewing despite ambient light and pollution. The peak is normally above the level of the low cloud cover often seen in San Jose.

• The peak provides a stunning view to the west of the Valley of Heart’s Delight, now better known as Silicon Valley. To the east, the Sierra’s can be seen on a very clear day.

• Despite its proximity to the 10th largest city in the U.S., Lick Observatory has kept up with the times. After 120 years of operation, it remains among the most productive research observatories in the world.

• While the 36” refractor was the centerpiece in the early days, Lick also houses many modern telescopes, including the Shane 120-inch reflector, the Nickel 40-inch reflector, the Crossley 36-inch reflector, and the Automated Planet Finder which will search for Earth-like planets around nearby stars.

A Bit of History

In 1887, Lick’s body was buried under the pier of the telescope. A brass tablet bears the inscription, “Here lies the body of James Lick.” Lick’s story in itself is endlessly fascinating, but we’ll leave that for a later issue.

Personal View

For a short time in my younger days, I worked in Silicon Valley and lived at an apartment complex built on the site of James Lick’s mansion and granary, which are national historical landmarks. Small world.