Practical Aspects of Observing in Chile

Practical Aspects of Observing in Chile
---------------------------------------

Chile is a fantastically long country; if it were flipped around
the Equator, it would stretch from southern Alaska to northern
Guatemala, or from Denmark to Senegal in the Old World. The part
of most interest to visiting astronomers stretches from Santiago
to Antofagasta, corresponding to the coast from Los Angeles to the
southern tip of Baja California. The area is strikingly similar
to California both in topography and in climate, both being shaped
by the same tectonic forces and by congruent currents in the ocean
and atmosphere.

Almost all international flights land in Santiago, which is in the
Mediterranean zone, with long dry summers and short moderately wet
winters. Astronomers who live in Santiago are lucky, like those
who live in Southern California. The probability of clear skies
is high from October through April, and not bad during the winter.
But Santiago is 1/4 the size of Los Angeles; you can drive out of
the basin in an hour, and pretty much escape from light pollution
and air pollution in two hours. Nonetheless, most people who have
taken the trouble to fly to Chile specifically for astronomy prefer
to go a little farther north, into the Atacama Desert, where the
conditions are better yet.

The Atacama is generally considered to be the driest desert in
the world; most of it averages around 10-15mm of rain per year,
as compared to 40mm in Death Valley or 200mm in Phoenix, Arizona.
This translates to some of the scarcest cloud cover in the world,
much lower than anywhere in the U.S. Prevailing winds bring clean
air off the ocean, and the cold Humbolt Current keeps the air cool,
yielding stable seeing and delightful temperatures year-round.
There is a reason that half of the major observatories built in
the last few decades are sited in the Atacama!

As in California, the coast is blanketed by frequent fog
throughout the Atacama and well into the Mediterranean zone.
The fog supports fairly lush vegetation in some otherwise arid
areas, and it can come surprisingly far inland and reach well
up the hills. To be guaranteed good conditions, you need to
be well away from the coast and/or at reasonable altitude,
at least 1000 meters and preferably higher. Fortunately,
altitude is easy to come by in Chile; you are never out of sight
of mountains, or at least very large hills.

Tom Polakis has offered the following web sites, which show
conditions at the European observatories Cerro La Silla and
Cerro Paranal:

//www.eso.org/gen-fac/pubs/astclim/paranal/clouds/cloudyearly.gif
//www.eso.org/gen-fac/pubs/astclim/lasilla/index.html

As you can see, even the world's best observing sites still have
non-trivial cloud cover, which may be an important consideration
if you are making a short (and expensive) trip solely for the
purpose of astronomy, especially during the austral winter from
May through September, when cloud cover is at its highest. Paranal,
at latitude 24S south of Antofagasta, has significantly better
conditions than La Silla, at latitude 29S north of La Serena,
and no doubt Cerro Tololo, the southernmost observatory, is worse
yet -- although still better than any observatory in the U.S.

On the other hand, La Serena is a highly scenic 6-hour bus ride
from Santiago, or a short and cheap flight, whereas Antofagasta
is a full-day trip by ground, or a more expensive flight.
Moreover, La Serena is a lovely old city in a delightful setting,
well watered by rivers coming down from the crest of the Andes.
Farther north, water is truly scarce and things get really austere;
even at 6000 meters and higher, the mountains get hardly any snow,
and they are nearly devoid of vegetation from bottom to top.

Moreover, people coming from the northern hemisphere specifically
to observe the southern sky are likely to want to go as far
south as possible, consistent with decent observing conditions.

Where to observe in the Atacama comes down to three decisions:

* How far do you want to travel?
* Do you want to rent a car?
* Do you want to stay in a town, in a backcountry resort, or camp?

Frankly, much as I love camping, I would not recommend doing it for
a long period in the Atacama, especially not on a solo trip. The
area is just too austere, too hostile to human life. One would have
to carry an inordinate amount of water, and I think that daytime
activities would begin to flag after a few days.

Backcountry resorts are few and far between in hard desert. I did
find some promising places from La Serena south to the north edge
of the Santiago basin, but none of them was truly ideal. The
problem is that resorts tend to be in valley bottoms, and most
of the valleys in the area are too deep and too steep to yield
good horizons for astronomy.

The Flemish-born, Santiago-based amateur astronomer Daniel
Verschatse, whom I met and observed with near Vicuna, is eager
to open an astronomy inn similar to the ones in Arizona and New
Mexico, but his plans have not yet quite come to fruition. This
seems like an idea with tremendous potential; it could be the
answer to all of the problems. I hope it works out!

As for town-based observing, two towns come to mind: Vicuna, 50km
east of La Serena, in the southern fringe of the Atacama, and San
Pedro de Atacama, east-northeast of Antofagasta. I spent an
entire week in Vicuna, but everything I know about San Pedro is
hearsay. But several Vicuna-based astronomers assured me that
San Pedro has outstanding conditions, and considering how good
Vicuna is, that is pretty high praise.

Vicuna has several advantages. First, the situation is excellent,
aside from the fact that it is still in the area of the Atacama
that gets non-trivial rainfall (100mm per year). It is one of
the largest settlements so far inland, and it is surrounded by
hills that are more than high enough for good observing. The
valley is also open enough to yield decent horizons even from
the valley floor.

Second, the town is exceptionally friendly and pleasant, easily
the nicest place that I visited in Chile, and I visited some
pretty nice places. It is just the right size, around 20,000
people, providing every service you can imagine, yet small
enough so that you can walk across it kitty-corner in 15 minutes.
If you get sick of it, it is just an hour by bus down to La Serena,
and an hour by bus up the valley takes you to some incredible
scenery. Vicuna is also small enough, and ends sharply enough,
so that you can escape its light with a very modest trip. In fact,
even inside Vicuna, from the back of my hotel, I got eminently
respectable naked-eye views of the Magellanic Clouds and the
Milky Way.

Finally, Vicuna has a tradition of astronomy. You can see Cerro
Tololo from many points in town, and Vicuna has its own municipal
observatory on Cerro Mamalluca, 9km from town. Mamalluca was
started by Cerro Tololo, in return for Vicuna installing shielded
low-pressure sodium lights, but now it has a life of its own;
it is wildly popular among foreign and Chilean tourists alike.
Mamalluca offers "tours" in Spanish and English; the first night
I was in Vicuna, I went on the English tour. A tour lasts for
2 hours, not counting transportation to and fro, and consists
about 1/3 of lecture and 2/3 of observing, both naked-eye and
through telescopes. They try to keep the groups small, ideally
half a dozen, but they get bigger on busy nights, including
weekends and summer vacation. They have enough guides and
scopes to handle 3 or 4 groups simultaneously, and on busy
nights in the summer, they run four separate time slots, from
dusk to dawn. That's a lot of people!

I loved my tour. I even learned some things during the lecture,
notably about the Inca constellations. Also, something I
should have known but didn't, namely that you can find the
approximate location of the South Celestial Pole halfway
between Achernar and Alpha Centauri. And Luis, our guide,
was wonderful at the telescope; he reminded me for all the world
of myself manning a scope at a star party. He was so eager for
everybody to be excited by what they were seeing, to notice
the special features, and to be awed by the beauty. Early on,
before he knew that I was also an amateur astronomer, he saw
me listening to him with binoculars hanging around my neck,
and he urged me to stop listening and start looking through
the binoculars. Go ahead, you'll love it! I thanked him,
but kept on listening.

Luis and Cristian, another one of the guides, run a stall near
the center of town where they sell astrophotos that they have
taken with the equipment at Mamalluca, and with their own
equipment. If you are ever in Vicuna, go and chat for a while,
and buy a photo or two. They do some very nice work.

As for San Pedro de Atacama, it is high in the Altiplano, the
great plateau between the two high ranges of the Andes, at
one of the very few oases in the region. The oasis has
kept the area continuously settled for millenia; San Pedro
has one of the richest archaeological records in the world,
helped greatly by the fact that organic material lasts forever
in that climate. The great majority of prehistoric fabrics
still extant come from the Atacama.

Today, San Pedro exists mostly as a tourist center, the base
for exploring the numerous volcanos, geysers, salt lakes,
and other natural splendors in that region. It has several
features that make it promising for astronomy. First, it is
spang in the middle of the driest part of the Atacama. Second,
it is at an ideal altitude, 2400 meters, above a good chunk of
the atmospherebut not high enough to cause breathing problems.
Third, the area is flat or rolling, with excellent horizons.
Fourth, it is even smaller than Vicuna (5000 people), so the
lights are presumably even easier to escape. Finally, they
turn the electricity off at midnight, offering the unique
opportunity to explore pristine skies from the middle of a
town offering wide choice in hotels and restaurants.

------------------------------------

If you are really eager to do as much astronomy as possible in the
smallest amount of time, I believe that renting a car is the only
viable option at the this time, until somebody discovers an ideal
backcountry resort or Daniel Verschatse opens his astronomy inn.
That is rather frustrating, as Chile has certainly the best bus
system that I have ever seen: extensive, fast, cheap, and very
comfortable, more like trains in America or Europe than like
Greyhound buses. The bus from Santiago to La Serena cost me $8
on special sale; the theoretical full price is $12, but I bet
nobody ever pays that. Anyway, tolls alone would have cost me
over $12 if I had driven, to say nothing of gas, to say nothing
of the cost of renting a car. Internal flights are apparently
also frequent and cheap. If you plan to observe in the Atacama
and are in a hurry, it probably makes sense not to go into
Santiago at all, but just change planes at the airport and
fly straight to La Serena, Antofagasta, or wherever.

I resisted renting a car when I first arrived in Chile, for
several reasons. First, it is a significant expense ($45 per
day for a Ford Fiesta from Avis in La Serena during low season,
probably more in Santiago.) Second, this was my first trip to
South America, and I was eager to see as much as possible. But
when you travel by car, you are in a little private cocoon that
tends to cut you off from the rest of the world; public
transportation forces you to interact, and shows you a nice
cross-section of society at the same time. Finally, I just
don't like cars, in principle and in practice.

However, even in Vicuna, where circumstances were about as good
as they get, observing without a car was very limiting. Public
transportation is all very well, but it only goes where people
live, which typically isn't where you want to observe, and it
doesn't run at 4AM. I spent several nights observing at
Mamalluca, taking advantage of the shuttle that they run to
and from town, but then I was at the mercy of their schedule,
and during the week, they had only one time-slot per night,
restricting me to a mere two hours. On the other hand, they
did give me exclusive use of their 16-inch Dob one night, which
was pretty fine compensation. The last night I was there, I
arranged for a taxi to pick me up at 1AM, which doubled my
observing time. But I felt bad asking anybody to pick me up
at 3AM or 5AM. 1AM doesn't really count as late in Chile, where
people eat supper at 9PM and little kids are up until midnight.

If I had had a car when I was in Vicuna, I would have been able
to use one of several sites on the opposite side of the valley
from Mamalluca, towards Cerro Tololo, which everybody assured
me were far superior to Mamalluca -- farther from the town lights,
and not distracted by massive comings and goings, and the
associated lights. I did consider renting a bicycle, but all
the really good sites are up in the hills, on unpaved roads.
The thought of bicycling up a steep, dusty desert road with my
telescope, and down again in the dark, does not appeal.
Bicycling to Mamalluca is not allowed, for safety reasons.
I did scout out some promising-looking sites on paved roads
in the valley floor, but I never got around to using them.

Incidentally, in case anybody is wondering, I should point out
that Chile is a highly civilized country, and on the whole, very
safe. Roads, electricity, and communications are excellent,
food and water are completely safe to eat and drink, and
corruption is non-existent. Walking around the plaza or the
shopping area in the center of most towns, you could easily
imagine that you are in southern Europe -- in Italy, say.
It is only in the rural areas, where you see the disproportionate
amount of work done by hand, or in the slums on the edges of the
cities, that you realize that Chile has far more poor people
than any country so prosperous has any right to have. In that,
it resembles the United States, but poor people in Chile are
much poorer than poor people in the U.S., at least in material
terms. I cannot find any statistics, but Chile seems much
safer than the U.S. in terms of violent crime; certainly,
there are a lot more girls and young women walking alone at
night. However, I suspect that there is somewhat more in the
way of petty theft, pickpocketing, and break-ins; several people
warned me not to leave anything in my car overnight in Copiapo.
Then again, Copiapo is a mining town, and mining towns in the
U.S. can be rather rough, too.

Language was a real problem for me; to my undying shame, I have
never really learned Spanish. I find this unforgivable for any
American, and doubly unforgivable for me, who grew up in a largely
Spanish-speaking neighborhood in Manhattan. But there is no use
crying over the past; the job ahead of me is to learn Spanish
now. In any case, minimal as my Spanish is, it is better than
most Chilean's English. I met very few people in Chile
who really spoke English -- which did not surprise me. What
did surprise me is how few people speak just a tiny amount of
English, as I speak just a tiny amount of French. In any case,
my next trip, when I have some serious Spanish under my belt,
will be much more rewarding and less filled with constant,
petty frustrations.

One other potential problem worth mentioning is that the
cheaper hotels in Chile tend to be converted houses, and the
tradition is that they lock the door and you ring to be let in.
This could be a problem if you plan to arrive routinely at 4AM.
That is one of the reasons that I ended up at the fanciest
hotel in Vicuna, the Hosteria Vicuna, where my door opened
onto public space, rather than in one of the much cheaper but
perfectly adequate hotels. Fortunately, hotels in Vicuna are
about half the price of equivalents in La Serena or Santiago;
the Hosteria Vicuna cost about $40 per night for a very nice
room indeed. In general, hotels in Chile are not especially
cheap, and the cheaper ones tend not to be very nice.

--------------------------------------------------------

My choice of equipment was limited by my desire to get around
by bus; I didn't want to take more than I could carry comfortably
on foot for a mile or two. I hate travelling with more than
that in any case; it makes me feel as though my posessions
are controlling me rather than the other way around.

Anyway, to make a long story short, I ended up taking my 10x50
Celestron Ultima binoculars and my 100mm F/6 Orion achromat atop
a Unistar Light head and a Bogen 3021S tripod. For eyepieces,
a 30mm Ultima, my 8-24mm zoom, and a Barlow, which all fit in a
9x6x2.5-inch Rubbermaid container together with UHC filter, red
flashlight, and eye patch. Wil Tirion's Bright Star Atlas,
a few hand-printed charts (doubling as sketching paper) and
a dozen loose sheets of the unbound Sky Atlas 2000.0 folded
appropriately. This probably weighed twenty pounds total and
packed together with my camping gear and clothes into a large
internal-frame pack plus a soft case that my wife had made
for the telescope.

The Unistar Light works very well indeed for the 100mm F/6
achromat atop my little Bogen 3021S, except maybe when the tripod
legs are fully extended; vibration is (at least) proportional
to the height of the tripod, all other things being equal.
Indeed, I do not find the 100mmm scope very satisfactory on
the Unistar Light for standing use, even on a much heavier tripod.
The Bogen 3021S extends only to 33 inches, plus 12 inches for the
Unistar Light, so it can only be used in a sitting position,
and preferably sitting pretty low when observing near the
zenith. I frequently observe sitting on the ground, which I
find perfectly comfortable for an hour or two, but when I was
in Chile, I always found something to use as a low seat --
a rock, a bench from my hotel, whatever -- which made the
setup considerably more comfortable for long sessions.
Certainly beats standing all night!

All in all, I have concluded, the 100mm achromat atop the
Unistar Light and the Bogen 3021S is the ideal travelling
rig, except for the limitations of its aperture. A 100mm
apochromat would work better at high power, of course, but
the extra cost would be a major inhibitor, making me
constantly nervous about the scope when not in sight.
Not a good state of affairs when travelling for pleasure.
Still, 100mm is only 100mm. Some day, it might be nice
to build a travelling Dob; too bad that there are no small,
reasonably-priced truss-tube Dobs on the market. Alternatively,
I might try Oldfield So's trick of mounting an 8-inch SCT
atop the Unistar Light.

As for the binoculars, again 10x50 seemed just right. My
15x45 image-stabilized binoculars would have been far superior
if I hadn't been taking a scope, but with their lighter weight,
wider FOV, and freedom from batteries, the 10x50 make a better
complement to a scope, in my opinion. And I certainly wouldn't
want to travel without binoculars. For one thing, they provide
a backup in case something bad happens to the scope. And
particularly in an unfamiliar sky, the ability of binoculars
to give a quick overview of a huge area is utterly invaluable.

- Tony Flanders

(Tony Flanders) wrote in message m...
Practical Aspects of Observing in Chile
---------------------------------------


- Tony Flanders

Hi Tony,
I've been following your ORs and experiences south of the Equator with
great interest.

I went south a couple of years ago, to the twon of Alexandra on New
Zealand's Southj Island, at latitude 45° south. It's an excellent
observing location, skies around mag 6.5 (sometimes better, sometimes
a bit worse) and there are local astronomers as well as a 21" newt.
The observing site, next to an unused airport, is a 5-minute drive
from town.

I travelled more heavily than you did, taking a 13" dob with me. My
observations are posted he
http://observers.org/reports/2001.05.14.html
Of course, there was no language problem, and New Zealand is very
inexpensive for Americans. Bargain flights still seem to be available
on occasion.

I think the southern skies are more spectacular than ours, and
certainly worth seeing. I'm hoping to go south this summer if
circumstances permit.

Clear skies,
Shneor Sherman

(Shneor Sherman) wrote in message . com...

I went south a couple of years ago, to the twon of Alexandra on New
Zealand's Southj Island, at latitude 45° south. It's an excellent
observing location, skies around mag 6.5 (sometimes better, sometimes
a bit worse) and there are local astronomers as well as a 21" newt.

Interesting! The only other time I was in the southern hemisphere,
I spent most of my time in New Zealand. Unfortunately, I was
astronomically unconscious at that point in my life, for reasons
that are a total mystery to me now.

Anyway, much as I enjoyed my stay in N.Z. (about a month), I had
written it off for astronomy because I remember it as having very
fickle and rather stormy weather. But I had forgotten about the
area in the lee of the New Zealand Alps, which does indeed tend to
be pretty clear. I gather from your reports that you had an anxious
time with the weather, but lucked out for the most part.

Being at lat 45S instead of 30S would obviously be a big boon, and
a resident 21-inch Newt is an added attraction. But the near-
guarantee of clear weather in Chile (or Namibia, or to a lesser
extent Australia) are mighty attractive for what might be a
once-in-a-lifetime trip.

- Tony Flanders

(Tony Flanders) wrote in message m...
(Shneor Sherman) wrote in message . com...

I went south a couple of years ago, to the twon of Alexandra on New
Zealand's Southj Island, at latitude 45° south. It's an excellent
observing location, skies around mag 6.5 (sometimes better, sometimes
a bit worse) and there are local astronomers as well as a 21" newt.

Interesting! The only other time I was in the southern hemisphere,
I spent most of my time in New Zealand. Unfortunately, I was
astronomically unconscious at that point in my life, for reasons
that are a total mystery to me now.

Anyway, much as I enjoyed my stay in N.Z. (about a month), I had
written it off for astronomy because I remember it as having very
fickle and rather stormy weather. But I had forgotten about the
area in the lee of the New Zealand Alps, which does indeed tend to
be pretty clear. I gather from your reports that you had an anxious
time with the weather, but lucked out for the most part.

Being at lat 45S instead of 30S would obviously be a big boon, and
a resident 21-inch Newt is an added attraction. But the near-
guarantee of clear weather in Chile (or Namibia, or to a lesser
extent Australia) are mighty attractive for what might be a
once-in-a-lifetime trip.

- Tony Flanders

I was told that the weather was unseasonably bad...but it was well
worth it in any case. Just seeing two huge galaxies hanging in the sky
is amazing. But the other spectacular objects are breathtaking. I did
have a difficult time with the upside-down constellations. IMHO, any
amateur who can should travel south. In Australia, arrangements can be
made to rent an 18" (and smaller telescopes are also available).
Clear skies,
Shneor Sherman

David wrote in message ...
Tony,
thank you for your time to write this down for us.
It only increased my desire to try a similar trip once in the future.

I am wondering if somebody would be able to organize a travel party,
either here from SAA readers and/or from various Yahoo groups.


David

David,
For those of use who are married, possibly with children, a travel
party such as you suggest would very helpful in assuring domestic
tranquility. My wife would not accompany me to New Zealand because,
she said, I'd be up all night and sleep during the day, leaving her to
fend for herself, as she has no interest in astronomy. With a group,
non-interested spouses and children have other people to spend time
with...
Clear skies,
Shneor Sherman

(Shneor Sherman) wrote in message . com...

I did have a difficult time with the upside-down constellations.

Yeah, it's weird, isn't it? I mean, we northern observers are used
to watching constellations like UMi and Cas rotate 360 degrees, or
Orion rotating 150 degrees (or whatever it does). You wouldn't
think that it would be so hard to recognize (say) Ares or CMa or
Sag when it is upside-down. But it is.

It helps to turn your head upside-down, insofar as that is possible.

- Tony Flanders