Disciplines of the Imagination

Las Campanas Observatory, Chile (January 6, 2006)

As +Rurousha often writes, the best part of blogs are their comments. I fully agree with this statement, and I am happy when long threads of comments populate the entries of this blog. My post about magnolias and life on extrasolar planets was especially rich with interesting discussions. One thread, initiated by +Grace Monte de Ramos, ended up mentioning astrology, and was closed by a very interesting comment by +Marj Evasco about the "disease of literalness" and the "disciplines of the imagination". It made me think for days... and finally spurred me to write a few words about astrology.

Las Campanas Observatory

For most of history, astronomy was the theoretical framework for astrology; which in turn was the practical application of astronomy. Astrology was taught in universities, where the astronomy faculty was required to make astrological predictions, as well as personal astrological charts for the university benefactors (the local princes). This was not just another chore (like serving in yet another faculty committee): it was the main raison-d'etre for these astronomy positions. The astronomers were willing partners in this activity not just because it was the source of their salary, but also because it promoted their prestige, continuing a millenarian tradition started by the priests of long extinct civilizations. Uraniborg, for example, was built with great expenses as Tycho Brahe observatory by the king of Denmark. During construction it absorbed 1% of the danish GDP, which is huge if you think that the Apollo project at its peak (in 1965) was just 0.8% of the US GDP. The reason for such an investment was for the renown astronomer to generate astral charts to guide the policy of the kingdom. Galileo himself was well known for his astrological work, and got in trouble from time to time because of the vehemence of his predictions. Doing science while simultaneously dabbling in the occult was not a unique characteristics of astronomers: chemistry has its roots in alchemy. The great Isaac Newton spent more time in his alchemic search for the philosopher's stone (to transmute base metals into gold), that he did to formulate the laws of physics. Newton was a prolific writer: he left more than 10 million words (enough for 150 full size novels). Only 20% of this corpus was about science and his activity as Master of the Mint; the larger fraction was about his heretical religious views and his work in alchemy. The extent of Newton's involvement in secret arts was such that John Maynard Keynes (the famous economist and collector of Newton's writings) opined that he was "not the first of the age or reason, but the last of the magicians".

Magellan Telescope

The fact that the founding fathers of science practiced what we would now call magic and superstition should not be seen as the original sin of science; it is rather an evidence of its strength. Newton, Galileo, Tycho were men of their times. During their lives there were no factual reasons to believe that the ideas of alchemy, or astrology, were unfounded. Their greatness was in transcending the supersticious foundations of the culture in which they lived to lay down the foundations for the scientific method, a revolutionary evidence-based approach to the physical world. The scientific method was what made ultimately possible to separate myths from reality, something that only came to fruition with the Age of Enlightenment. Astrology turned out to be unfounded: the only two celestial bodies that can possibly have a physical action on Earth are the Sun and the Moon (tides). Furthermore, the whole technical framework for astrology (constellations and geocentric cosmology) have long been proven to be an illusion. The irony in all this is that it was Tycho's superior data for the position of Mars that were crucial to ultimately disproved his own geocentric view . The same fate befell on Alchemy: it is not possible to convert iron into gold with chemical means, although the feat is possible, at great costs, with nuclear reactions. The irony here is that Newton started the science that showed how his main life efforts were in vain. Science is a self-healing process: ideas that are falsified by experiments are ultimately rejected, and replaced by new paradigms that can better explain and agree with the data. Science is a purely empirical endeavor.

Yet, I agree that science is also a discipline of the imagination. It is a way to abstract the stark reality of the physical world and give it a life, meaning and aesthetic value in the realm of the mind. It is an instrument to appropriate the elegance of the universe and describe it in mathematical form. It is a way of transcending the imperfections of the human nature and aspire to the divinity of the cosmos. This is why many scientists that are not religious in traditional terms still have a sense of sacred (e.g. Einstein secular religion). Astrology is no science, and it has no basis in the physical world. Still, it can be a fascinating discipline of the imagination. Astrology and the esoteric world are precious windows on the human mind. Like myth making, or religion. They tells us about the strategies devised by our minds to cope with their existential problems, and come to term with their mortality.

Furthermore, reading the horoscopes after the Sunday comics is fun. As long as, of course, they are not taken literally and considered as a factor for deciding government policy. ;-)

Las Campanas, Chile (January 6, 2006)

Of Grapes and Formidable Women

Valle del Elqui, Chile (January 13, 2006)

It is almost time to leave Chile, the longest and narrow country in the world. Barely a strip of land, with tall mountains rising straight from the Pacific ocean all the way to the sky. And long glacial valleys, green and fertile at the base, crowned by stark-naked mountains, like monuments of rainbow-painted rocks.

Side road in the Elqui Valley

The Elqui valley is not just for UFO, telescopes and mysterious magnetic energy. It is in fact one of the best vineyards in Chile, famous for pisco, a special kind of brandy made with the local grapes. Pisco was developed in this region of Chile and Peru by the first spanish colons in the XVI century, as a substitute for orujo, a pomace brandy that had to be imported from Spain. With the foundation of the port city of La Serena at the head of the Elqui valley, the local pisco became world famous. Pisco is now Chile's national drink. As you can see in the photo above, the secret for these grapes is the very fertile bottom of the valley, surrounded by semi-desertic mountains in a hot dry climate. Exactly what you need to grow rich grapes with a high sugar content, ideal to produce a high grade alcohol brandy like pisco. The whole valley is terraced for grape production, and the stark contrast between the green vines and the red and blue mountains is quite a spectacle. This is a drive worth taking.

And driving is exactly what I did in the last day of my 2006 trip to Chile. Despite its violent past during Pinochet's dictatorship, Chile is now a very safe country, at least outside large degraded urban areas (which are dangerous almost everywhere in the world). Differently than in a certain latin american country I am familiar with, it always felt safe driving alone even in remote areas (see small photo on the left). Mountain's people tend to be nice; they like to hear your stories and tell their tales.  I had fun taking hitchhiker on board during my drives, and listen to their stories. Like the one of the two local kids working in the city that were going back to their mountain's village to visit their grandmother. Or the two american girls returning to La Serena after spending some time in one of the new age communes in the valley. 

Old truck

Chile's progress since the return of the democracy has been quite remarkable. January 2006, the time of my last visit, was at the height of the presidential elections that were ultimately won by Michelle Bachelet. A physician, she is a separated mother of three that describes herself as agnostic. In a deeply catholic country that only allowed divorce in 2004 this makes her election even more remarkable. Bachelet didn't come to politics by chance. The daughter of a loyalist air-force general under the Allende government, she was imprisoned and tortured, together with her mother, in the infamous "Quatro Alamos" detention center by Pinochet secret police (her father was also arrested and died under torture). After years of exile in Australia and East Germany, she was allowed to return to Chile where she completed her medicine studies. For "political reasons" she was however not allowed to practice as a doctor, and she ended up working in a NGO helping the children of the desaparecidos. That ultimately lead to her work as an assistant to the deputy Minister of Health and then of the minister of Defense. In 2000, virtually unknown, she was named by President Lagos Minister of Heath, with the task to eliminate, within 100 days, the long waiting lists in the saturated chilean hospital. She succeeded to reduce them by "only" 90%, which caused her to offer her resignations (promptly rejected). Among her other acts as Health Minister she authorized the distribution of the morning-after pill to victim of sexual abuse, an extremely controversial decision in a country where abortion is still illegal under any circumstances (not even to save the heath of the mother). In 2002 she became the Defense Minister, one of the first women in the world to held that post. When Lagos retired she was asked to run for the presidency for the Socialist party, and won by 53.5% at the second turn. Her presidency was so popular that at the end of her mandate in 2010 she had 85% approval ratings. After working as head of the United Nation's Entity for Gender Equality and the Empowerment of Women, she has been elected president for a second term in June 2013, with 73% of the votes.

The electoral campaign was in full swing as I was driving through Vicuña, the main town in the Elqui valley. The streets were plastered with large posters of Bachelet next to the image of another woman, Gabriela Mistral. Vicuña's most illustrious daughter, Gabriela Mistral is one of the two chilean to win the Nobel prize for Literature, together with Pablo Neruda. Chile is a land of poets, and of formidable women.

Valle del Elqui, Chile (January 13, 2006)

40 Billion Earths and the Elqui Valley UFO

Valle del Elqui, Chile (January 13, 2006)

It is estimated that there are 40 billion Earths in the Galaxy. That's the number of rocky planets that orbit a solar-type star at just about the right distance to allow a comfortable surface temperature for life. This number is not a guess, but a measurement. It is an estimate that comes from one of the most daring experiments that astronomers have done in the last decade: the Kepler Space telescope.

You have probably heard about it. It is a smallish spacecraft that was sent in orbit around the Sun (that is, in deep space, not low Earth orbit like that weakling of Hubble) staring at stars to catch them blink. Stars have many reasons to flicker, but the blinking Kepler was designed to search-for is related to the dance that planets make around their stars. Imagine this: a far away star is going about minding its own business with its cohort of little planets, like mother hen with its chicks. You know how chicks are, they never stay quiet, they go round and around their mom in incessant circles: so are these planets revolving around their parent star. Imagine now that this alien planetary system is so perfectly aligned, by pure chance, that at every orbits these planets transit in front of the star, as seen from afar. Each time this happens, the star will appear ever slightly to dim, because of the little planet blocking some of its light by standing in front of its disk. Like a mini-eclipse, except that we call it transit. Kepler was designed to continuously stare at 150,000 stars in our Galaxy, hoping to detect the tell-tale sign of these chance events, and use them to infer the presence and size of the planets that could be causing them. As improbable as this geometry is, Kepler found 246 of these luckily aligned planets, with other 3,538 probable extrasolar planets awaiting confirmation.

USS Enterprise!!!

You may wonder why all this effort, and what does it means. Well, the whole point of the exercise was to extrapolate the number of the discovered planets over the whole number of stars in the Galaxy,  to estimate the fraction of stars that host Earth-like planets orbiting in what we call the habitable zone. The Kepler Space Telescope told us that this fraction is about 22%: about one star in four has at least one planet like Earth. Multiply this fraction by  the total number of solar-type stars in our Galaxy, which is about 200 billion, and you get the 40 billion Earths through the whole Milky Way. It turns out that this fraction is one of the most important factors (fp∙ne) in the famous Drake equation. Envisioned by the astronomer Frank Drake, the equation lists all the factors to be taken into account to estimate the number of technological civilizations with whom we could communicate. Many other factors are involved, some of them easy to measure (the star formation ratio in the Galaxy) and other very hard to guess (e.g. how long a civilization will last before disappearing, or becoming so advanced that would be completely out of reach with our technology). The Drake equation, in its apparent simplicity and hidden complexity, spawned the search for extraterrestrial civilization which is SETI. A Don Quixote-sque enterprise, for certain, but based on science and with a huge potential payoff. 

As you probably know, so far we didn't find any evidence that these other civilizations are actually there. This is unfortunately a true statement, despite innumerable claims of alien abductions, UFOs and various conspiracy theories of government coverups and contacts of the third kind. Measuring the fraction of habitable planets, and finding it so high, gives however confidence, 40 billions times confidence, to be precise, that life could have evolved somewhere else in out Galaxy. The distances may be enormous and direct contact may be impossible but, as Arthur C. Clarke once famously said, the idea that we could be alone in the Universe is equally terrifying than the possibility to find somebody else!

Valle del Encanto, Chile (January 12, 2006)

PS: what has this all to do with Chile and mountains? Well one of the world-renown hotspots of UFO sightings is precisely in a valley near La Serena. The Elqui valley is famous for its mysterious positive energy, for being the center of Earth magnetism (uh?) and for the crash of an extraterrestrial spaceship on a nearby hill with inevitable government coverup (the Roswell of Chile). Even the prehistoric petroglyphs in the nearby Valle del Encanto show a clear depiction of several Enterprise-class spaceships from the Star Trek universe (see small photo above, what else could they be, right?). All this two steps away from the Cerro Tololo Inter-american Observatory (CTIO), hosting one of the largest telescopes in the world. Well, either we astronomers don't look to the sky as much as we pretend, or we must be part of the big conspiracy to hide the truth which is out there. Which I solemnly deny to be the case.

A Forest in the Desert

Norte Chico, Chile (January 12, 2006)

There is a rainforest in the desert. At the southernmost tip of the Atacama desert, the mountains and the ocean join in a daily ritual. The moist currents from the sea meet the cold air from the desert night: it is from their union that the camanchaca is born. The camanchaca is a rainless cloud, that sticks to the bottom of the valleys and moves inland like a dense bank of fog. It is a harbinger of life, as it brings moisture to one of the most arid deserts in the world.

Parque de Fray Jorge

A hundred kilometers south from La Serena, the camanchaca sustains the northernmost Valdivian temperate rain forest of Chile. Within the Parque Nacional Bosques de Fray Jorge, the forest is a remnant of the last glacial period, when densely wooded areas were common along the whole andean chain. With the retreat of the glaciers the trees have largely disappeared, replaced by the dry terrain of the Atacama desert. This north, only a few holdouts of the primeval forest are left, nourished by the clouds arising from the ocean. The forest at Fray Jorge is one of them (photo at the left, shot late in the day when the fog had already morphed into clouds, dissipating in the afternoon sun). To get to the park you drive south from La Serena along the Panamericana Highway, and then turn 90 degrees along a dirt road towards the coast (photo below). It is a surreal experience, driving towards a forest surrounded by a barren landscape of cacti framed by bare mountains of naked rocks. I though I was lost more than once: my trip was before universally available GPS, and my only guide was a  low resolution printout of an early version of google maps. I finally reached the gate of the park, where a custodian collected the small entrance fee, checked that I knew the closing hour of the gate and that I had a watch with me. I said: "no hay problema, tengo la hora acqui en mi celular", showing him my battered Treo (no iPhones and touch-screen smart phones at the time). He was quite impressed by my phone, opened wide his eyes and smiling said "pero eso no es un celular, es un avion!", before lifting the gate and letting me in.

Friendly goats

The park is quite large (100 square km), and only a small fraction is actually forested. The rest looks like the usual dry landscape of this part of Chile, more like the large photo on top. An accessible trail allows a short walk on the rim of the mountains facing the ocean. The trees are dense and beautiful, a stark contrast with the arid scrubland around. I spent some time on the lookout, and then walked back to the car, just in time before the entrance gate would be locked. On my way to the highway I lingered in the desert, paying visit to the imposing cacti flowering in yellow and red seasonal bloom. Near a creek I found company: a small friendly herd of goats. They were roaming around in the barren plains at the base of the coastal mountains, until they found a large saguaro-like cactus and sat there in its shade. They are shown on the left, minding their business while occasionally checking on the weird guy with the camera walking around, possibly worried that I was, yet again, lost.

I went back to the car and drove away, in the direction of the blue mountains rising over the horizon.

Norte Chico, Chile (January 12, 2006)

Dry Desert and Clear Skies

Norte Chico, Chile (January 8, 2006)

We live at the bottom of a turbulent ocean, an ocean of air that we call atmosphere. It is a thin layer, if we look at it from space: an almost impalpable skin. Still, for all creatures living at the bottom of this sea, it is a nurturing elixir, our sustenance, the source of life. For us astronomers, however, is more like a scourge!

Let me qualify. It is not that we astronomers don't like to breathe, that's not the issue. The problem is that this turbulent ocean is, well, turbulent. It is like looking up from the bottom of a swimming pool: you can still see the lifeguard looking down from the side of the pool, but she is all blurred. You would never tell that she has that concerned face as she is trying to figure out what the hell are you doing at the bottom, until she jumps in and pulls you out and your pool card is revoked. Crap! It is the same with the atmosphere, it blurs and distorts the light coming from the stars, making our billion-dollar telescopes worthless (well, almost). And that's not even all of it: even in crystal-clear days the sky is not really transparent: the pesky molecules that makes up our air are very selective about the color of the light they allow to pass through. In the visible range, the one the human eye can see, it is not so bad. But go slightly redder or slightly bluer (we have nice CCD detectors for that) and the atmosphere becomes increasingly opaque. The main culprits for this are some notorious molecules we all know about: water vapor, ozone and CO2. These molecules are particularly nasty in the infrared and microwave range: this is not surprising since they are powerful greenhouse gasses. They let Sun's radiation in, but don't allow the thermal infrared radiation from the ground to escape back to space. The heat is trapped and the poor planet overheats. If you are a climatologist, you should be concerned about CO2, which of these three molecules is the one we are artificially messing up to level not seen in millions of years. If you are an astronomers, however, your enemy is water. If you want to see the infrared stars you need to find the place with the least amount of water vapors on top of your head. Hence astronomers quest for dry high mountain deserts.

This is what northern Chile offers to astronomers. A dry highland desert with little or no precipitations, and a very dry air that is as transparent as it gets without leaving the atmosphere altogether and launch your telescope to space. The Las Campanas observatory is at the edge of the largest of the Chilean dry highlands: the Atacama desert. You can see the views in the photos of this post: rocks, sands and a sturdy fauna and flora perfectly adapted to an environment where it may not rain for years: an astronomer's dream, and a beautiful muse for a photographer looking for unadulterated landscapes of the nude Earth.

Norte Chico, Chile (January 8, 2006)

Old Stars Never Die, They Slowly Fade Away

Las Campanas Observatory, Chile (January 9, 2006)

Like old soldiers in the WWII army ballad, most stars never die, they slowly fade away.

The fate of stars is assigned at birth. A few stars are born very massive, and they live a fast and furious life, burning bright like candles lit on both ends. After just a few million years, they run out of nuclear fuel and collapse under their own weight. This collapse rebounds in a final stupendous explosion, so bright that can be seen across the Universe. These are the events that we call supernovae. Massive stars are however very rare, and most stars are instead born with a low mass, like the Sun or even lighter. These stars burn quietly for a very long time, many billions of years, ending their life in a much less dramatic way. When they feel that the end is night, they become giants: swollen balloons of warm gas, deep red jewels in the night sky. They pulsate, like a tired throbbing heart, one single beat per year. They also smoke: a sooty fog blown out by a slow inexorable wind. A smog so thick that ends up engulfing the star and its planets in a dark cocoon, hiding them from sight. That's when these old stars disappear, fading away from the visible universe behind their curtain of death. Even for stars, however, nothing is forever. The veil finally dissipates, revealing the hot cinder remnant of the star, surrounded by a glowing nebula like a butterfly emerged from it cocoon. We call these fleeting beauties planetary nebulae.

Magellan telescope

I am telling you this story because the primary scientific reason for my 2002 trip to Chile was to spy on these cocoons where old stars hide in their final moments. For this project we used the newly built Magellan telescope (photo on the left), equipped with a new camera we shipped all the way from Arizona: an infrared camera, because with light of this invisible color we can lift the veil surrounding these stars, revealing their secrets. There are many reasons why we want to understand the how and why these stars end their like in such a mysterious way. For starters, the Sun is one of them, although it will take several more billion years before all this will happen. The more pressing reason, however, rests in the nature of the holy smoke that these old stars spew around in their final disappearing act. Talking about smoke was not a poetic license on my part, but rather a quite literal description. For many of these stars the composition of these cocoons is rich in carbon and many complex organic molecules: the building blocks of life. Studying the death of these stars will lead to understand how life arose in the Universe. We literally are stardust, and these stars are the fairies that seeds an otherwise sterile Galaxy with the ingredients of life.

Las Campanas Observatory, Chile (January 8, 2006)

Looking for Exomoons and Diapers along the Panamericana

Along the Panamericana, Chile (May 4, 2002)

My first trip to Chile happened in 2002, and I was scheduled to use the newly built Magellan "Baade" 6.5 meters aperture telescope. Getting time on large telescopes is hard, so the usual observing runs at facilities like the twin Magellan telescopes don't last more than a few nights. If you get good weather you return home with a treasure trove of data which will feed your research for months. If the gods of rain are instead against you... well you have gone all the way to the end of the world, and back, for nothing. My 2002 trip to Chile was however different. I went there to help testing a camera never before used on that telescope, so we had plenty of engineering time to debug our instrument. Lots of time: a 20 nights run. Spending such a long period at the telescope is cool, until of course you realize that for that same long time you are stuck on top of a mountain, in some deserted isolated place.

OGLE Telescope Dome

Salvation in this 2002 run came in the form of a friend of mine, Grzegorz, an astronomer from Poland working for the Optical Gravitational Lensing Experiment (OGLE). This project uses the small telescope shown in the photo on the left. OGLE is a very cool program, scanning the sky in the search of a rare phenomenon in which a star acts as a lens for a background object. The physics of the phenomenon is related to Einstein's General Relativity: massive objects deflects light due to their gravitational field. Even the Sun does it: if you could see the stars during daytime you would notice that the ones near the Sun would appear in a slightly different place than where they are supposed to be. This is an experiment that you cannot normally do, because during daytime there is no way to see the stars. Except of course when there is an eclipse, in which case the glare of the Sun is blocked by the Moon and you can see the sky behind as if it was night time. This measurement was in fact first accomplished in 1919, and was the first test to demonstrate the validity of Einstein's theory of gravity. OGLE tries to do the same but using other stars rather than the Sun, when they randomly align with stars farther away. This is an extremely rare event, because it requires an almost perfect alignment, but if you look continuously at a large number of stars, sooner or later you are bound to get lucky. For this reason OGLE looks at the two Magellanic Clouds (dwarf galaxies close to the Milky Way) and at the bulge of our own Galaxy, where millions of stars can be surveyed without having to cover an impossibly large area. When one of this millions of stars flickers because of this gravitational lensing effect, one can derive the properties of the lensing object from the characteristics of the flickering. With this techniques we can see very faint stars that we would not be able to detect directly, and count them, which is important to have a reliable census of the kind of stars that populate our Galaxy. Sometimes we even get some surprise: in some rare cases these flickering events may be followed by a secondary, fainter flicker, due to a planet orbiting the star that caused the primary lensing event. One month ago the OGLE people got an even bigger surprise: a peculiar lensing event that could have been caused by a "free floating" giant planet with an Earth-size exo-moon, roaming the Galaxy alone after having been ejected from their native planetary system. This could be the very first detection of a moon in another solar system.

Given the nature of the OGLE survey, Grzegorz is often stuck at Las Campanas Observatory for months on end. When that happens he bring to the observatory his whole family, which in 2002 meant his wife and a very young child. It also means that he has a car, which is a necessity if you need to be able to get away from the self-contained, but very utilitarian, environment of the observatory. Which brings us to the second part of the title of this story. At some point during their stay, Grzegorz run out of diapers for the kid, and decided to drive down the mountain in a quest for diapers in the villages around the observatory. I went along with him.

You can imagine how the search went. As described very well by Kelly Clancy in this essay, the area around Las Campanas is a dry highland desert. The only inhabited centers that you will encounter along the Panamericana highway that is crossing the region are tiny villages with tin-roof houses. They are mostly living off subsistence agriculture adapted to the very arid climate of the area. The large photo on top and the panoramic at the bottom show the typical landscape: naked mountains crossed by dirt roads, and in the fall season rows of aji peppers left to dry under the Sun. The villages have only small stores where you can find basic needs products. While that apparently includes lots of Nestle canned food, the inventory doesn't really include single use diapers: these are luxury items that make very little sense when you can rather use a washable cloth, reusable as many times as you want. It didn't take long to realize that the people we asked for the diapers were quite baffled by our inquiries. Diapers (or the lack thereof) are a #FirstWorldProblem.

In the end we did find some temporary solution to Grzegorz's problem, and drove back to the observatory, but not before stopping on a side road where we saw the petroglyphs in the small photo on the right. As it happens, the Panamericana highway retraces the the same route of an ancient Inca trail, a road that for a thousand years has enabled the commerce between the center of the Inca civilization in Cuzco, and these villages at the periphery of the empire. These same villages are still there, and they will still fight the parched highland desert well after we will have abandoned our telescopes and returned to our ivory towers.

Sideroad off the Panamericana Highway, Chile (April 30, 2002)

Mountains and Telescopes in the Chilean Andes

Las Campanas, Chile (January 6, 2006)

The north of Chile is the astronomer's paradise, and hosts many of the largest aperture telescopes looking at the southern skies (the northern sky is best seen from Hawaii or the US southwest). There are two main reasons for this: dry high mountains and political stability. The high plateau in northern Chile are shielded by the Andes from the easterly moist winds: raising above the inversion layer in the atmosphere, the Andes stops the Clouds on their east side, leaving deserts to the west and forests (the Amazon) and grasslands (the pampa) to the east. Lacks of clouds means transparent nights and a sky with little turbulence, in turn guaranteeing excellent observing conditions for most of the year. Political stability means the possibility of building long-term expensive projects, and the creation of the necessary infrastructures. The dirty secret of astronomy is that Chile was chosen not because it was the best absolute place in the Andes, but because Pinochet's dictatorship was guaranteeing long-term commitment in exchange for investor countries to overlook the human right violations in the country. In the end, modern democratic Chile got a good deal out of the observatories (Chile is now the world's country with more guaranteed telescope time in the world, and an astronomer's mecca), but at the time I suspect there was a lot of looking the other way from the community.

Las Campanas, Chile

I have been in Chile several times, visiting the Las Campanas Observatory (LCO). LCO is in the "Norte Chico", which is a region one hour (by small plane) north of Santiago, but not as north to be on the border with Peru (the "Norte Grande"). The closest city is La Serena, a nice town on the coast, renowned vacation place thanks to its long sandy beaches. Two other observatories are in the area: the observatory of Cerro Tololo (managed by the NOAO, the organization providing open access time to US-based astronomers) and the La Silla Observatory (managed by ESO, the European Southern Observatory). LCO is instead a partnership of the Carnegie Observatories with the Smithsonian Astrophysical Observatory (SAO): my ticket to the telescope was through SAO, where I had been employed for many years. I will post photos of the LCO telescopes at some other time, but you can see the telescope domes of La Silla in the panoramic below: can you find the white dots on the crest of the mountain on the left? The photo was taken from the minibus driving me from La Serena to Las Campanas. The large photo above and the small one on the left show the sunset from the LCO terrace, shot the first night I arrived at the site. As you can see the area is very isolated, with just a few little villages in the valleys below, guaranteeing no light pollution that would blind the delicate astronomical instruments. This is actually a serious issue for modern astronomy: the main sites in Arizona, for example, are in a constant struggle to keep down light pollution from the Tucson metropolitan area, which are bright enough to seriously degrade the site. To prevent this issue, the Chilean government has recently established a vast protected area around the observatory sites in the Atacama desert (this is in the Norte Grande), to favor the construction of the new 30 meters telescope (the European Extremely Large Telescope, or E-ELT) that Europe is building there.

Norte Chico, Chile (January 6, 2006)

Las Campanas Observatory

Las Campanas Observatory (Jan 10, 2006)

Since the subtitle of my photoblog is "Photos of a traveling astronomer", I better post some travel related astronomy image. The one above shows some of the telescopes at the Las Campanas Observatory. Las Campanas is a large observatory near La Serena, Chile. The facility is managed by the Carnegie Observatories, and hosts a number of telescopes, including the du Pont telescope (large dome on the right), the Swope Telescope (isolated dome on the left) and the Warsaw telescope used for the OGLE survey (elevated dome in the center-right). The Warsaw telescope is one of those cases showing how you can do great science even with small telescopes (the primary mirror of the telescope, 51 inches diameter, is not completely out of reach for a very dedicated amateur). The OGLE survey it performs looks at two nearby satellite galaxies (the Magellanic Clouds) and towards the center of our own Galaxy for the flickering of stars caused by other objects passing in front of them. As Einstein showed with his theory of general relativity, massive objects (e.g. a star of a planet) deflect light similarly to an optical lens. This phenomenon (called gravitational lensing or, in this case, microlensing due to the relative small mass of the lensing object) causes the brightness of the lensed object to briefly increase as its light is "beamed" by a lensing object passing in front of it. 

Magellan Telescopes, Chile (Jan 8, 2006)

By looking for microlensing signature caused by the chance alignment of a "lens" with a distance star in the Magellanic Clouds or the Galactic Center, it is possible to perform a census of very small mass and dim "lenses" that may lurk closer to home, and that would not be possible to detect otherwise. In this way several very low mass stars, and even extrasolar planets, have been detected. As a bonus, the OGLE surveys monitors the variability of million of stars, and has amassed one of the most complete catalog of light-curve of variable stars in the Magellanic Clouds, which I regularly use for my science. Another example is the HAT (Hungarian Automated Telescope) network, a collection of very small robotic telescopes dedicated to the search of exoplanets transiting in front of their parent star. The HAT telescopes were still not installed at the time I took the photo above. Missing from my picture are also the Magellan Telescopes, which are the twin large aperture telescopes (6.5 meters primary mirror diameter) in the small photo on the left. I was using one of them during the trip in January 2006 when I took the photos shown here.