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A Visit to Lick Observatory

What do you think of when someone says ‘observatory’? Maybe your own backyard roll-off. More likely, some remote high mountaintop sprinkled with giant domes and blessed with thin air and steady, inky-black skies, maybe in Hawaii or Chile. Surprisingly, though, the idea of putting an observatory on a mountain is quite a recent idea.

Many of the early observatories, even those housing large instruments, were in major cities. Think Greenwich near London; Pulkovo outside St Petersburg; Meudon in Paris. Arguably the first observatory to reject urbanity and head for the hills was Lick Observatory on Mount Hamilton in California.

But Lick isn’t just a first for location, in the late 19th C. it was also home to the world’s largest optical telescope and that great instrument is still there. Lick played a role in the Moon landings (right on topic for my 2019 visit) and still does research. Luckily for you, it’s an easy place to visit too – close to San Jose and an easy day trip from San Francisco.

History

James Lick, whose slightly unfortunate name the observatory takes, was born in 1796 on a Dutch farm in Pennsylvania. The legend goes that he fell in love with a local girl from another farm and asked for her hand in marriage. The girl’s father’s response was only if Lick had made his fortune first, which he then set out to do. Lick spent years in south America, made the demanded fortune trading, and returned to find the girl married to someone else.

Eventually, Lovelorn Lick moved from South America to California with a small fortune in both gold and chocolate. The latter sold so well that Lick persuaded Domingo Ghirardelli to move to San Francisco too.

Lick rapidly increased his wealth by buying up land in San Francisco at the time of the Gold Rush. Eventually, he became so rich and owned so much of downtown that when he wanted to build himself a memorial, a giant Pharaoh’s pyramid in the heart of the city seemed a good idea.

Luckily for San Francisco, Lick had a scientist friend who dissuaded him. That friend regularly went observing in the hills above San Jose and suggested to Lick that he might like to build an observatory (then fashionable for rich amateurs) and make his eternity home there instead. In the event Lick left a substantial chunk of his fortune to establish the observatory on Mount Hamilton ($700,000 – the equivalent of $15 million today).

James Lick died on Oct 1st 1876 at eighty years old, but his observatory wasn’t finished until eleven years later in 1887. Famously, Lick was exhumed and re-interred in the newly-built brick base for the Great Refractor and there he remains. His eponymous observatory built itself a giant refractor and went on to make important discoveries in both astrophysics and planetary science. Half a century later, the observatory built another leading instrument.

Lick Observatory has figured in popular space history too: it was the location for the laser bounced off the Moon as part of the Apollo program.

In the last few decades Lick has again embarked on important research, this time in the field of extra-solar planets – initially using a sensitive spectrograph attached to its 120” reflector. Then in 2013 Lick commissioned a specially built 2.4 metre telescope, the Automated planet Finder, fitted with a Doppler spectrograph specifically for detecting exoplanets.

Lick Observatory’s founder is interred in the pier base for the 36” refractor.

In more recent history, Lick has done seminal research into exoplanets.

Getting There

Lick is handily close to the Bay Cities, especially San Jose. Highway 130, a turn off Interstate 101, leads all the way up Mount Hamilton, passes right through the middle of Lick Observatory and down the other side. A straight road through the suburbs of San Jose, it leads out into live-oak foothills and meadows, then becomes the most winding of roads as it gradually climbs towards the white domes you can see from miles off.

The reason for all those hairpins is that they had to keep the gradient below 6% for the wagons used to cart everything up the mountain to Lick (including the Great Refractor and it mount in 1886).

Parking at Lick is fairly limited, but there are a few spaces on the left of the road beyond the main building. If you book an open evening, you need to wait until they open the main gates, after which you can drive right up by the dome for the 36” and park in front (where the views are incredible).

Lick’s exhaustingly winding access road – built for the convenience of wagon teams.

Mount Hamilton Road runs right through the site.

What to see

Perhaps the biggest draw of Lick Observatory for most visitors are its spectacular views. Lick is set atop 4200ft Mount Hamilton and hosts a 360° panorama. On a clear day you can see the Sierras to the east, with Half Dome in Yosemite (120 miles away) visible on the very clearest, its direction thoughtfully marked on the railing behind the dome for the Great Refractor. To the west, in front of the main building, lie foothills and the urban sprawl of San Jose. Beyond gleams the Bay, the coast range rising behind. Many go to Lick simply to stand on the deck and watch the Sun set into that vast view.

There are other attractions – a gift shop and a shady courtyard café behind the main building, but mostly it’s about those views.

For those interested in telescopes, Lick has at least three historic examples and you can visit two of them: the famous 36” Great Refractor (the world’s second largest) and the 120” Shane reflector.

There are various smaller domes containing a variety of other instruments around the site and some interesting displays on the lobby walls too.

Most visitors come for the sunset.

The main observatory building has a grand air, interesting displays like this early Pacific Standard Time chronograph.

Lick’s first major instrument, the Crossley Reflector, lies in a dome at the south end of the site.

The 36” Crossley Reflector

The first telescope installed at Lick was a 36” reflector, gifted by an English politician named Edward Crossley from Yorkshire. The telescope had been built in 1879 by one Andrew Ainslie Common who used it to make pioneering long-exposure deep sky images of the Orion Nebula from his backyard roll-off shed observatory in Ealing (a London suburb, where I was born incidentally). The 36” reflector is regarded as perhaps the earliest astrograph.

In 1886, Crossley bought the 36” when Common got aperture fever and built a 60”. Crossley moved it to Halifax and seems to have used it little before advertising it for sale in 1895. The director of Lick contacted Crossley, who eventually agreed to donate the telescope. Funds were raised for shipping and the Crossley Reflector, along with its dome, crossed the Atlantic to become the largest instrument in America for some years.

However, the Crossley Reflector hasn’t been used since 2010 and isn’t open to the public. You can see the British-built Crossley dome, lying below the main site on a small peak to the south of the main complex.

Dome for the 36” refractor, day and night.

Visitors line up for a look through the eyepiece of the 36” Great Refractor.

The 36” Alvan Clark Refractor

The largest dome on the south side of the road houses Lick’s most famous instrument – the 36” aperture Great Refractor.

The history of the Lick 36” refractor began in 1880, when the glass blanks for its doublet lens arrived from Paris by ship and work started to grind them at the famous Alvan Clark works in Massachusetts.

The finished lenses were transported to the west coast by train, then up the mountain by horse and cart, to arrive onsite in 1886. The long delay was because one of the lenses broke on the journey and it took many attempts to grind another

The 36” saw first light in 1888 and was for some years the largest telescope in the world. It made some important discoveries too, including Jupiter’s moon Amalthea by E. E. Barnard soon after it was commissioned.

The 36” objective is the second largest Alvan Clark ever made and the largest still in operation (the largest, the 40” at Yerkes, is no longer open for visits or views). The ‘Great Refractor’, as it’s also called, is a huge and magnificent thing, with a 57-foot long tube and a gigantic equatorial mount.

To add to the slightly Steampunk, Gothic-novel ambience of the place with its parquet floor, riveted plates, capstan wheels and spiral stairs, is the presence of James Lick himself, seeing out eternity in the base of the pier. You can visit the simple plaque on his grave by climbing down narrow wooden steps by the side of the dome and walking under the giant girders that hold up the (once moveable) floor.

The Great Refractor is now mostly used visually for outreach and is open to tour groups in the summer, but gets heavily booked up. Viewing through it is a great experience and highly recommended. The moving floor isn’t working, so be aware you have to climb a big ladder to the eyepiece. Meanwhile, the telescope operator has to climb the pier with a harness and hard hat to operate the mount!

The 36” still gives incredible views, but does need some restoration work to avoid going the same way as the 40” at Yerkes

You can visit the 36” on a tour, or better yet book onto one of the ‘Summer Series’ events which often combine a concert with an evening’s viewing (get in quick, because tickets sell out quickly in April every year). I have written a review of the 36” and the experience of viewing through it here.

Front and back of the 120” Shane Reflector dome. Building for the Hamilton spectrograph at the Shane’s coudé focus is on the right.

Walkway around the Shane dome gives a panoramic view. I met a famous astronomer here (not pictured!)

Views of the 120” Shane reflector, showing its adaptive optics laser and prime focus.

Instruments at the Cassegrain focus.

Tank for re-coating the main mirror lies in the basement of the dome.

Placard about the adaptive optics laser and the little hut used by observers to shut it off if a plane or satellite strays into its beam.

The 120” (3m) Shane Reflector

Across the other side of the mountain top, on the north side of Highway 130 is another cluster of buildings, including an even larger white dome which houses an even larger telescope, a reflector this time, the Shane 120”. That dome, all 275 tons of it, has a double skin to help insulate the telescope from the day’s heat.

Like the 36”, and despite being less well known, the Shane 120” was among the largest optical telescopes in the world after first light in 1959. It also has the distinction of using one of the first mirrors made of the then-new material Pyrex (great for oven-ware for precisely the reason it’s good for mirrors – it is virtually free from expansion when it heats up).

The Shane’s 120” mirror – 15 inches thick and weighing four tons - was cast and ground as a trial run for the (much more famous) 200” at Mount Palomar. The whole ‘scope and mount weigh 145 tons.

Like many modern big research telescopes, the Shane has three focus points for the placement of instruments: prime, cassegrain and coudé. The latter directs light out to a separate building containing the high-precision Hamilton spectrograph, which pioneered research into exoplanets.

The earlier big reflectors at Mount Wilson look like an Edwardian bridge, with a mass of small girders. In contrast, the Shane has an Art Deco simplicity about the design, same as the more famous Palomar 200”: a simple truss-tube to support the mirrors, held by an elegant fork mount in a retro-brown to match the yellow truss-tubes.

The Shane is just a human lifespan newer than the Great Refractor, but looks (and in many ways is) a thoroughly modern instrument by comparison: it still does research and benefits from a pioneering laser adaptive optics system – a first when deployed in 1996 (since replaced with a 2nd generation system).

Just outside the dome, on the edge of the summit plateau and with a great view, is a strange little hut like an old telephone booth but with a glass roof. This hut is for an observer to shut-off the laser (with a ‘big red button’, they said) when an aircraft or satellite threatens to stray into its beam: a boring job but a well-paid one, they jokingly told us. This is necessary because the laser is quite a powerful one (10W), thousands of times more powerful than a typical laser pointer!

Descending into the dark basement of the Shane dome, visitors are shown a huge red tank where they re-aluminise its mirrors.

Going in the other direction, it’s possible to walk out onto a gantry around the dome for spectacular views across the site, to the 36” dome and the hills beyond. The other domes are opening for the night as you watch. The gantry is quite narrow though, so not ideal if you suffer from vertigo.

After my visit, I stayed on a for a while to capture some long-exposures of the observatory and the stars. Nobody seemed to mind. A perfect end to my evening at Lick before facing the long and tedious drive back down all those bends, dodging jaywalking raccoons.

Lick observatory is well worth the tortuous drive up from Fremont, especially if you’ve booked an evening observing on the 36” Great Refractor.