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.
