CA -- Palomar Mountain -- Palomar Observatory:
- Bruce Guthrie Photos Home Page: [Click here] to go to Bruce Guthrie Photos home page.
- Recognize anyone? If you recognize specific folks (or other stuff) and I haven't labeled them, please identify them for the world. Click the little pencil icon underneath the file name (just above the picture). Spammers need not apply.
- Copyrights: All pictures were taken by amateur photographer Bruce Guthrie (me!) who retains copyright on them. Free for non-commercial use with attribution. See the [Creative Commons] definition of what this means. "Photos (c) Bruce Guthrie" is fine for attribution. (Commercial use folks including AI scrapers can of course contact me.) Feel free to use in publications and pages with attribution but you don't have permission to sell the photos themselves. A free copy of any printed publication using any photographs is requested. Descriptive text, if any, is from a mixture of sources, quite frequently from signs at the location or from official web sites; copyrights, if any, are retained by their original owners.
- Spiders: The system has identified your IP as being a spider. I love well-behaved spiders! They are, in fact, how most people find my site. Unfortunately, my network has a limited bandwidth and pictures take up bandwidth. Spiders ask for lots and lots of pages and chew up lots and lots of bandwidth which slows things down considerably for regular folk. To counter this, you'll see all the text on the page but the images are being suppressed. Also, a number of options like merges are being blocked for you.
Note: Permission is NOT granted for spiders, robots, etc to use the site for AI-generation purposes. I'm excited for your ability to make revenue from my work but there's nothing in that for my human users or for me.
If you are in fact human, please email me at firstname.lastname@example.org and I can check if your designation was made in error. Given your number of hits, that's unlikely but what the hell.
- Help? The Medium (Email) links are for screen viewing and emailing. You'll want bigger sizes for printing. [Click here for additional help]
- Specific picture descriptions: Photos above with "i" icons next to the bracketed sequence numbers (e.g. " ") are described as follows:
- PAL_110718_074.JPG: 1908: Mt. Wilson 60-inch telescope:
Under the supervision of George Ellery Hale, and through grants from the Carnegie Institution of Washington, the Mount Wilson 60-inch telescope is completed and sees "first light." It is the world's largest telescope, and with the exceptionally calm and stable atmosphere above the Los Angeles basin, astronomers can see fainter and more distant objects that ever before. Harlow Shapley uses this telescope to measure the size of our galaxy (the Milky Way) and the solar system's position in it.
- PAL_110718_078.JPG: 1928: Grant for 200-inch telescope:
Hale (pictured to the left) secures a grant of six million dollars from the International Education Board, a funding agency endowed by the Rockefeller Foundation, for "the construction of an observatory, including a 200-inch reflecting telescope... and all other expenses incurred in making the observatory ready for use." Unlike the Mt. Wilson observatories, which are operated by the Carnegie Institution, the 200-inch is administered by the recently founded California Institute of Technology (CalTech). Hale and his teams of astronomers, engineers, and opticians set to work.
- PAL_110718_082.JPG: 1930-34: Site selection:
With the increasing light pollution from Los Angeles, Mount Wilson is no longer an ideal site for an observatory. Hale starts a survey of less populated locations for the planned 200-inch telescope. Sites in Arizona, Texas, Hawaii, and South America are considered, but the early favorite and eventual winner is a site at an elevation of 5,600 feet on Palomar Mountain, 100 miles southeast of Pasadena, California. Hale buys one hundred sixty acres of land from local ranchers and the U.S. Forest Service.
- PAL_110718_084.JPG: 1934-36: Telescope structure design:
Once the mirror specifics are finalized, engineers start designing the telescope's structure. It will weigh hundreds of tons, but must be able to move smoothly and accurately to follow celestial objects as they transit across the sky. While tracking, the mirror must maintain its shape to a few millionths of an inch. Several revolutionary and ingenious engineering concepts are implemented into the design to meet these requirements, including the oil bearing system, the Serrurier truss, and the mirror support cell.
- PAL_110718_089.JPG: 1936: Dome construction:
While the road to the mountain is improved, and water and electricity are installed, construction work begins on the 200-inch dome. Cottages are built for some of the important personnel, while other workers live in barracks that are part of a nearby cattle ranch.
The telescope piers are anchored to the bedrock 22 feet below, while the dome supports go about 7 feet into the overlying granite. During the summer, everyone on the mountain helps pour concrete, including several Caltech undergraduates and the observatory cooks. Work proceeds briskly, and the dome is completed in less than two years.
The finished dome is 41 meters (135 feet) tall, 42 meters (137 feet) in diameter. It is a remarkable coincidence that these dimensions are similar to those of the Parthenon in Rome. The dome weighs approximately 1,000 tons, with a plate steel exterior and aluminum panel interior, separated by four feet to allow for dome venting. Two 125-ton shutters cover the opening seen in the center image and slide open at night to allow light through the slit and into the dome.
The top section of the dome rotates on two circular rails. You can see one pair of the thirty-two "trucks" on which the dome rides through the window at the top of the stairs. Many people who have ridden on the rotating dome have commented that it feels smoother than most elevator rides.
- PAL_110718_091.JPG: 1936: 18-inch Schmidt Telescope in Operation:
The small Schmidt camera is put into service, used primarily to monitor nearby galaxies for supernova explosions. The performance of the Schmidt design is so good that the project supervisors discuss building a larger Schmidt telescope to photograph the entire night sky. These two telescopes will complement the 200-inch perfectly, since they can quickly take long exposures of large areas of the sky. Until such wide-field images are available, astronomers must make educated guesses about where to look to find new, interesting phenomena.
- PAL_110718_092.JPG: 1936: Mirror Transport:
The mirror blank, with only a rough flat front surface, is shipped across the country on a special train from New York to Pasadena, always traveling slower than 25 miles per hour. The telescope project has captured the public imagination, and thousands of people line the train tracks to watch this special cargo. Guards are posted around the mirror during overnight stops to prevent any damage to the disk. The trip takes sixteen days.
- PAL_110718_094.JPG: 1936-47: Mirror Grinding and Polishing:
In the optics lab at Caltech, the front surface of the mirror is ground to the approximate concave form required. Using successively finer polishing grit, the opticians then carefully smooth the surface, constantly using optical tests to compare it to a perfect paraboloid shape. It is slow and painstaking work. To make the final mirror, almost 10,000 pounds of glass are polished away, including the top several inches that contain "scar tissue" left over from the casting and annealing process.
- PAL_110718_096.JPG: 1937-39: Telescope Construction:
Components of the telescope are constructed at sites all over the country and then shipped to the mountain for assembly inside the dome. Parts from Westinghouse's Philadelphia factories, Corning's New York glass foundries, and Caltech's and Carnegie's Pasadena labs have to make their way up to the mountain summit. On many occasions, national train routes are rescheduled as these parts travel across the United States. The major telescope components are shipped by boat through the Panama Canal, with the Navy's help.
Many of the alrge telescope parts are built in shipyards, which are the only places capable of working on such large pieces of steel. This also leads to the battleship grey paint scheme for the telescope.
To the left, you see the open telescope tube. On the bottom left are the "arms." The west arm would eventually house the declination axis motor, while the east arm was available for a variety of instruments. In the bottom right image are the two arms and the central component of the giant "horseshoe" (seen in its entirety in the upper right).
- PAL_110718_099.JPG: 1938: 48-inch Schmidt Started
Using funds and technology from the 200-inch telescope, work on the 48-inch Schmidt (now called the Samuel Oschin Telescope) begins. Corning casts the main mirror for the telescope and Pasadena opticians make the refractive corrector plate. This smaller telescope, named the Samuel Oschin telescope in 1987, has a wide viewing area (thirty-six square degrees). This field-of-view lets astronomers make detailed maps of the entire northern sky and allows them to systematically select targets of interest for study with the more powerful 200-inch.
- PAL_110718_100.JPG: 1941-45: World War II:
Telescope production halts because most of the engineers and scientists, as well as their laboratories, are reassigned to war-related projects. Not even mirror polishing continues during the war. The 200-inch disk is stored and protected by timbers for three years. After the war concludes, telescope work restarts in September of 1945. After three months of cleaning the labs, mirror polishing resumes. Most of the pre-war telescope workers do not continue with the project, so a new crew must learn the routines.
- PAL_110718_102.JPG: 1947-49: Mirror Transport and Installation:
The 200-inch mirror is transported from Pasadena to Palomar on November 18-19, 1947. The 40 ton cargo requires three diesel tractors to push it up the mountain. Despite a storm, which nearly aborts the transport, the 125 mile trip is completed in 32 hours.
After removing the concrete disk (now located outside the dome) that was used to test the support structure, engineers install the mirror. Initial imaging results are promising but not ideal. It takes two years to finish polishing, aligning, and adjusting the mirror.
- PAL_110718_104.JPG: 1948: Dedication Ceremony:
Although the 200-inch telescope is still not yet fully operational, it is dedicated on June 3rd and formally named in honor of George Ellery Hale, who passed away in 1938. Almost one thousand people attend the dedication, including many dignitaries from around the world. The first demonstration of the telescope and dome includes a ride on the dome as it spins. The ride is smooth enough to confuse some into thinking the telescope floor is rotating.
- PAL_110718_107.JPG: 1948: First Light on 48-inch:
The 48-inch Samuel Oschin Schmidt Telescope is completed and for many years it would be the largest Schmidt telescope in the world. The first official photograph is taken in September and its image quality is good enough that it is used in Hubble's galaxy atlas. One year later, the 48-inch begins the first Palomar Observatory Sky Survey, which maps the entire northern sky. This catalog would later become the basis for the Guide-Star Catalog used by the Hubble Space Telescope. A second (digitized photographic) sky survey would start in 1985 and finish 15 years later. To the left, Edwin Hubble peers through the finder telescope of the 48-inch in 1949.
- PAL_110718_109.JPG: 1949: Full-time Science Observing Begins:
Thirteen years of mirror polishing finally grind the "Big Eye" to the desired form. Edwin Hubble takes the first photographic exposure with the 200-inch in January. In October, the telescope is made available full-time to the astronomers from Caltech and the Carnegie Institution, twenty-one years after the Rockefeller grant. Pictured to the left is a few minute exposure of the open dome underneath star trails and the summer Milky Way.
- AAA "Gem": AAA considers this location to be a "must see" point of interest. To see pictures of other areas that AAA considers to be Gems, click here.
- Wikipedia Description: Palomar Observatory
From Wikipedia, the free encyclopedia
Palomar Observatory is a privately owned observatory located in San Diego County, California, 90 miles (145 km) southeast of Mount Wilson Observatory, on Palomar Mountain in the Palomar Mountain Range. It is owned and operated by the California Institute of Technology (Caltech). The observatory currently consists of four main instruments: the 200 inch (5.08 m) Hale Telescope, the 48 inch (1.22 m) Samuel Oschin Telescope, the 18 inch (457 mm) Schmidt telescope, and a 60 inch (1.52 m) reflecting telescope. In addition, the Palomar Testbed Interferometer is located at this observatory.
The Hale Telescope:
This 200 inch (5.08 m) telescope is named after astronomer George Ellery Hale. It was built by Caltech with a 6 million dollar grant from the Rockefeller Institute, using a Pyrex blank manufactured by Corning Glass Works. The telescope (the largest in the world at that time) saw 'first light' in 1948. The American astronomer Edwin Powell Hubble was the first astronomer to use the telescope for observing.
The Hale Telescope is operated by a consortium of Caltech, Jet Propulsion Laboratory, and Cornell University.
For a history of the 200-inch (5.08 m) instrument's construction find a copy of The Perfect Machine by Ronald Florence, ISBN 0-06-018205-9. Richard Preston wrote a critically acclaimed nonfiction novel about the Hale telescope and the astronomers who use it, called First Light.
Although the Hale Telescope has been used to discover hundreds of asteroids, it should be mentioned that its tenth-scale engineering model still resides in Corning, New York, home of the Corning Glass Works, and was used to discover at least one minor planet, (34419) Corning †.
Other telescopes and instruments:
* A 60" (1.5 m) f/8.75 telescope. It was dedicated in 1970 to take some of the load off of the Hale Telescope. This telescope discovered the first brown dwarf star.
* The 48" (1.22 m) Samuel Oschin Schmidt Camera. The dwarf planet Eris was discovered with this instrument.
* A 24" telescope completed in January 2006.
* An 18" (0.4 m) Schmidt camera. Comet Shoemaker-Levy 9 was discovered with this instrument.
* The Palomar Planet Search Telescope, a small robotic telescope dedicated to the search for planets around other stars.
* The Palomar Testbed Interferometer which allows for very high resolution measurements.
Palomar Observatory Sky Survey:
The Palomar Observatory Sky Survey (POSS), sponsored by the National Geographic institute, was completed in 1958 (The first plates were shot in November 1948 and the last in April 1958). This survey was performed using 14 inch² or (6 degree)² blue-sensitive (Kodak 103a-O) and red-sensitive (Kodak 103a-E) photographic plates on the 48 inch (1.22 m) Samuel Oschin Schmidt reflecting telescope. The survey covered the sky from a declination of +90 degrees (celestial north pole) to -27 degrees and all right ascensions and had a sensitivity to +22 magnitudes (about 1 million times fainter than the limit of human vision). A southern extension extending the sky coverage of the POSS to -33 degrees declination was shot in 1957 - 1958. The final POSS consisted of 937 plate pairs.
J.B. Whiteoak, an Australian radio astronomer, used the same instrument to extend this survey further south to about -45 degrees declination, using the same field centers as the corresponding northern declination zones. Unlike the POSS, the Whiteoak extension consisted only of red-sensitive (Kodak 103a-E) photographic plates.
Until the completion of the Two Micron All Sky Survey (2MASS), POSS was the most extensive wide-field sky survey ever. When completed, the Sloan Digital Sky Survey will surpass the POSS in depth, although the POSS covers almost 2.5 times as much area on the sky. POSS also exists in digitized form (i.e., the photographic plates were scanned), both in photographic form as the Digital Sky Survey (DSS) and in catalog form as the Minnesota Automated Plate Scanner (MAPS) Catalog.
One of the current ongoing research programs at Palomar is the Near-Earth Asteroid Tracking program.
This program makes use of the Palomar Quasar Equatorial Survey Team (QUEST) Variability survey that began in the autumn of 2001 to map a band of sky around the equator. This search switched to a new camera installed on the 48 inch (1.22 m) Samuel Oschin Schmidt Telescope at Palomar in summer of 2003 and the results are used by several projects, including the Near-Earth Asteroid Tracking project. Another program that uses the QUEST results discovered 90377 Sedna on November 14, 2003, and around 40 Kuiper belt objects. Other programs that share the camera are Shri Kulkarni's search for gamma-ray bursts (this takes advantage of the automated telescope's ability to react as soon as a burst is seen and take a series of snapshots of the fading burst), Richard Ellis' search for supernovae to test whether the universe's expansion is accelerating or not, and S. George Djorgovski's quasar search.
The camera itself is a mosaic of 112 Charge-coupled devices (CCDs) covering the whole (4 degree by 4 degree) field of view of the Schmidt telescope, the largest CCD mosaic used in an astronomical camera when built.
In September 2007, a team of astronomers from the US and the UK released some of the clearest pictures ever taken of space. The pictures were obtained through the use of a new "adaptive optics" system which sharpens pictures taken from the Mount Palomar Observatory.
* Ira Sprague Bowen, 1948–1964
* Horace Welcome Babcock, 1964–1978
* Maarten Schmidt, 1978–1980
* Gerry Neugebauer, 1980–1994
* James A. Westphal, 1994–1997
* Wallace Leslie William Sargent, 1997–2000
* Richard Ellis (astronomer), 2000–2006
* Shri Kulkarni, 2006–?
The Palomar Observatory is an active research facility. However, parts of it are open to the public during the day. Visitors can take self-guided tours of 200-inch (5.08 m) telescope daily from 9 a.m. to 4 p.m. There is a visitor's center and a gift shop on the grounds.
The observatory is located off State Route 76 in northern San Diego County, California, is two hours' drive from downtown San Diego, and three hours' drive from central Los Angeles ( UCLA, LAX airport ).
Although the surrounding area is mostly undeveloped, there is a big hotel and casino approximately 15 miles (24 km) from the observatory.
- Bigger photos? To save server space, the full-sized versions of these images have either not been loaded to the server or have been removed from the server. (Only some pages are loaded with full-sized images and those usually get removed after three months.)
I still have them though. If you want me to email them to you, please send an email to email@example.com
and I can email them to you, or, depending on the number of images, just repost the page again will the full-sized images.
- Connection Not Secure messages? Those warnings you get from your browser about this site not having secure connections worry some people. This means this site does not have SSL installed (the link is http:, not https:). That's bad if you're entering credit card numbers, passwords, or other personal information. But this site doesn't collect any personal information so SSL is not necessary. Life's good!
- Photo Contact: [Email Bruce Guthrie].