Kitt Peak is the oldest national observatory in the United States. It was founded in 1958, when the National Science Foundation signed a lease with the Tohono O’odham Nation, upon whose land the observatory resides. 

Before Kitt Peak, observatories were either privately funded, such as Lowell Observatory, founded by Percival Lowell, or university managed, such as the Harvard College Observatory. But with the rise of the Cold War in the 1950s, there was a desire to have an American space program, which would be supplemented by a national astronomy program. Kitt Peak was chosen as the location because of its high altitude and clear calm skies. It was also reasonably close to the University of Arizona, which had (and still has) an excellent astronomy program.

The McMath-Pierce solar observatory. Credit: Harvey Barrison

Over the years some of Kitt Peak’s status as the flagship U.S. observatory has faded a bit as newer and larger telescopes have been built elsewhere, the history of Kitt Peak is still evident its wide range of telescopes. There are optical telescopes ranging in size from 0.9 meters to the 4-meter Mayall telescope. There are radio telescopes, including a 25-meter telescope that is part of the Very Long Baseline Array, and there is even the McMath-Pierce solar observatory, which observes the Sun during daylight hours.

If you are ever in the area, the observatory does have daily tours and night viewing sessions. It’s one of the more accessible major observatories, and well worth the visit.

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The Milky Way is visible from anywhere on Earth. While it makes for a lovely milk-like glow across the sky, it is also filled with gas and dust that can limit our view of certain parts of the sky. While we can map out where certain gas and dust is through the Milky Way, making an accurate map is challenging because much of it is cold and diffuse, making it difficult to observe. But with the rise of submillimeter radio astronomy, that’s changing. 

Cold gas and dust emits faint light in the submillimeter range, so to study this material we need good radio telescopes. Unfortunately our atmosphere (mainly water vapor) absorbs these wavelengths, so the radio telescopes need to be located in a dry region at high elevations, such as at Chajnantor plateau in northern Chile. The most famous telescope at Chajnantor is the Atacama Large Millimeter/submillimeter Array (ALMA), which is an array of about 60 antennas. But just down the way from ALMA is the Atacama Pathfinder Experiment (APEX), which has been mapping the gas and dust of our galaxy.

The APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) has been scanning the Milky Way at submillimeter wavelengths, and has just released a full map of our galaxy. You can see one of their images above, which shows the wonderful complexity of the Milky Way, with fine tendrils of gas and dust. Creating a map such as this will not only help astronomers better understand our own galaxy, but also allow astronomers to better take the effects of our galaxy into account when looking beyond our neighborhood of stars.

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In astronomy, we often lament the rise of light pollution. As populations rise and our use of artificial lighting becomes greater, we lose the dark skies of our ancestors. We can see this effect through the increasing difficulty in observing a night sky filled with stars. While we can’t see radio waves, radio astronomy also suffers from an increase of light pollution.

The mobile radio van to detect stray radio signals.

While the radio quiet zone is often portrayed as a region where modern society can’t encroach, but that’s actually not the case. Folks in the region have internet just like everyone else. They can stream Netflix, stalk Facebook and all the rest of modern society just like everyone else. They just don’t have wifi or cell phones. Except for the “always in your pocket” access to the web, things aren’t that different than any rural area in the US. Even then, there are folks who have wifi in their home and such. Though it’s discouraged, the radio quiet zone can’t control what people do in their own home. It only regulates things like radio stations and mobile phone towers.

Most of the efforts within the region is making sure that things like faulty wiring and old transformers don’t fill the air with loud stray radio signals. These can be addressed by proper equipment maintenance and sometimes a bit of shielding. But we also live in a world that is increasingly radio loud. Bluetooth and wifi are now used not only in laptops and cell phones, but in exercise monitors, smart watches and even batteries in smoke alarms. As the “internet of things” increasingly connects objects to each other, keeping the radio quiet zone truly quiet will become an increasing challenge.

All of these radio loud devices pose no harm to us personally, any more than an electric lamp does. They can even make our lives more convenient. But that convenience comes at a cost to radio astronomy. Modern radio telescopes are so sensitive that even snapping a picture with a digital camera near the telescope can flood the detector with radio light. Hence the need for a radio quiet zone.

It’s the only way radio telescopes can have truly dark skies.

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If a typical mobile phone was placed on the surface of Mars, it would be the brightest radio object in the night sky. It’s not that mobile phones are generating massive amounts of radio energy, but rather that astronomical radio objects are extraordinarily faint. That’s why we need super-sensitive radio telescopes, and why some radio telescopes need to be protected against stray radio signals.

One solution is to create a radio quiet zone, where the use of radio and microwave technology is severely limited. In the United States, a National Radio Quiet Zone was established in 1958 to protect radio telescopes at Green Bank observatory in West Virginia. It’s a 34,000 square kilometer region spanning parts of Virginia and West Virginia. In the Zone there’s no cell coverage, no wifi, and limited internet. Near the telescopes themselves even digital cameras are too radio loud to be used.

It’s also where I happen to be heading for the rest of this week. I won’t have access to the web while I’m away, and I don’t have a backlog of posts, so this site will also be entering a kind of radio silence. Posts will start back up again once I’m back on Monday, but until then enjoy the break from my usual broadcast.

See you all when I’m back.

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In the mountains of Chile I experienced the brightest night sky I’ve ever seen. We normally seek dark skies for astronomy, but here the sky is so dark and clear that it seems ablaze with stars. The Milky Way overhead is so brilliant it seems to cast shadows. It is a sight so humbling it’s difficult to put into words.

The Chilean sky with the Zodiacal light in the background. Photo by Peter Detterline

Chile resides in a “sweet spot” for modern astronomy. Steady winds from the Pacific ensure skies relatively free from turbulence, and Chile’s arid mountain range provides plenty of crystal clear nights. Combined with the Chilean government’s efforts to limit light pollution, you have the makings of excellent astronomy. While professional astronomy has been active in Chile for decades, the recent surge of “big astronomy” projects such as the Atacama Large Millimeter/submillimeter Array (ALMA) has led to a rapid growth of astronomy in the region.

There’s also been interest in promoting these efforts to the general public, which is why I had the opportunity to visit the region. Along with eight others I was selected to be part of a National Science Foundation project known as the Astronomy in Chile Educator Ambassador Program (ACEAP). The goal of the project is to bring educators to Chile to get a first-hand look at several observatories so that they can tell people about their experience. Saying yes to the offer was one of the easiest decisions I’ve ever made.

The ACEAP Team. Clockwise starting from far left: Ryan Hannahoe, Petter Detterline, Jim O’Leary, Michael Prokosch, Sergio Cabezon, Brian Koberlein, Renae Kerrigan, Vivian White, Charles Blue, Sarah Komperud and Shannon Schmoll. Photo by Tim Spuck.

Our trip took us from the capital city of Santiago to La Serena (near Gemini and CTIO), then north to the Atacama where ALMA is located. One of the things we noticed early on was a strong interest in amateur astronomy. Santiago’s surrounding mountains ensure that the city can be troubled by smog at times, but it also means you don’t have to travel far from the city to reach dark skies. As a result, there are several “tourist” observatories in the region.

At Cerro Mayu Observatory the artwork is astronomically aligned. Photo by Mike Prokosch.

These observatories tend to integrate artwork and astronomy in fascinating ways, whether it’s the inviting space of Observatorio Astronomico Andio, or the astronomically-aligned Cerro Mayu Observatory. They also aren’t limited to metropolitan regions. In the small town of San Pedro in the heart of the Atacama desert you could find street vendors selling tours of the night sky.

Of course it’s the big telescopes that dominate in Chile. By 2020 more than two thirds of the world’s astronomical infrastructure will be in Chile. Four our trip we focused on just three sites: Gemini South and SOAR on Cerro Pachón outside of La Serena, CTIO on nearby Cerro Tololo, and ALMA in the Atacama desert near San Pedro.

Approaching Gemini South. Photo by Peter Detterline.

Standing in front of the Gemini South mirror. Photo by Sarah Komperud.

Gemini South is an 8-meter telescope that has been in operation since 2000. It uses adaptive optics to gather clear images in the visible and near infrared. It’s name derives from the fact that it has a northern twin on Mauna Kea in Hawaii. As Gemini South maps the southern skies, Gemini North maps the northern skies. Together they cover almost the entire sky. Their specialty is observing the spectra of astronomical objects using both long-slit spectroscopy and integral field spectroscopy. These allow us to study the rotational motion of extended objects such as galaxies and nebulae.

While we only spent a short time on Cerro Pachón, we got to spend two nights on Cerro Tololo. The temperatures were unseasonably mild for early winter, and the night skies were perfect.

Cerro Tololo is dominated by the 4-meter Victor M. Blanco telescope, built in the early 1970s. A main research project of the Blanco observatory is the Dark Energy Survey, which looks for supernovae to study the dynamics and large scale structure of the universe. Near the Blanco telescope are several telescopes that are part of the Small and Medium Research Telescope System (SMARTS). One project that utilizes these telescopes is the CTIO Parallax Investigation, which searches for dim dwarf stars in our solar neighborhood.

The Blanco telescope at night. Photo by Renae Kerrigan.

Since then dozens of telescopes have been built on the site, including a cluster of smaller telescopes that form the “mushroom farm.” Many of these are tenent telescopes that rent space on the site.

It was on Cerro Tololo that we really had the opportunity to get a feel for what these remote observatories are like. We weren’t simply given a tour and sent on our way, but resided with the astronomers and workers. The observatory is remote, so it’s removed from the bustle of everyday life. It has an exquisite beauty that moves some to compose music about the experience.

A zorro (Andean fox) eyes us cautiously. Photo by Jim O’Leary

Of course the observatory most of us looked forward to visiting was the Atacama Large Millimeter/submillimeter Array (ALMA). ALMA is a microwave radio observatory located in the remote Atacama desert. In order to observe such small wavelengths, ALMA was built on the Chajnantor plateau about 5000 meters (16,000 feet) above sea level.

ALMA antennas at Chajnantor. Photo by Mike Prokosch

ALMA consists of more than 60 12-meter antennas as well as 12 7-meter antennas. The 7-meter antennas are designed to be closely spaced, forming the Atacama Compact Array (ACA). Since the antennas use interferometry to create images of the sky, the ACA creates a wide sky view, while the larger array of 12-meter antennas allows us to focus in on particular objects. The antennas can be moved to different locations to allow for different scales and resolutions.

The correlator at ALMA. Photo by Tim Spuck.

The engineering of ALMA is incredibly ambitious. In order to combine signals from the antennas, a supercomputing correlator had to be built on the plateau. It is the highest altitude supercomputer on the planet. The correlator not only has to account for the arrangement of the antennas, but also the orientation of the Earth relative to the target object. As the Earth rotates, the effective separations of the antennas relative to the target change, and the correlator has to account for this in its calculations.

Sarah analyzes ALMA data. Photo by Peter Detterline.

While it was amazing to see some of Chile’s best observatories, what I really gained from the experience was how much modern astronomy is a human endeavor. While we often talk about breakthrough discoveries, or the amazing engineering of modern observatories, much of the work is done behind the scenes. People have to design and manufacture these observatories, and they have to be maintained and supported in order for the science to get done. Machinists, programmers, groundskeepers and security officers all play a necessary role.

There’s also the political machinations necessary for international collaborations. A large observatory such as ALMA is too much for one country to undertake. So ALMA is a collaboration between the United States (NRAO), Europe (ESO), East Asia (NAOJ) and the Republic of Chile. Its coordination has been likened to the United Nations.

And that’s the direction big science is taking. It’s only by working together that we can solve the unanswered questions of the universe.

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Before the 1960s, most major telescopes were in the northern hemisphere. The southern observatories that existed at the time were built more for convenience of access than clarity of skies. This was unfortunate since there are lots of wonderful objects in the southern sky such as the Magellanic clouds and Carina region of the Milky Way. So in 1962 it was decided to build a modern observatory on Cerro Tololo. It was to become the Cerro Tololo Inter-American Observatory (CTIO), but was often referred to as the “Chile Project.”

Construction of the Blanco telescope. Credit: CTIO.

In order to protect the region from development, 30,000 hectares (74,000 acres) of land surrounding Cerro Tololo were purchased for the project. Given its remoteness, an entire infrastructure had to be developed there, including water and electrical power.  The original plan for the site was to build a 1.5 meter telescope, but by the 1970s construction began on a 4-meter telescope. This became the flagship telescope on Cerro Tololo, and was named in honor of Victor Blanco in 1995. Blanco was the second director of CTIO, and was crucial to its establishment as a leading southern observatory.

A bit of music under the watch of Blanco. Credit: Jim O’Leary

Over the years other smaller telescopes have been installed on Tololo, and the Blanco 4-meter has been upgraded. Most recently the 520 megapixel camera array known as Dark Energy Camera was installed in 2012 as part of the Dark Energy Survey. The project studies dark energy through supernovae, baryon acoustic oscillation, and gravitational lensing.

Although there’s no more room for large telescopes on Cerro Tololo, there is room on other hills within the 30,000 hectares of CTIO. Most of the new construction focuses on Cerro Pachón, where the Southern Astrophysical Research telescope (SOAR) and Gemini South are located, and where Large Synoptic Survey Telescope (LSST) is under construction.

It looks like the Chile Project is likely to continue to grow for quite some time.

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There are more nearby dwarf galaxies than we thought, and that may answer a mystery of dark matter. Although the results aren’t yet peer reviewed, they come from the Dark Energy Survey, which found several nearby dwarf galaxies earlier this year. This latest work adds 8 more candidate galaxies to that list. 

The Blanco telescope at CTIO.

The Dark Energy Survey (DES) is being carried out at the Victor M. Blanco telescope in Chile, which I happened to visit this summer. As it’s name suggests, its main goal is to study dark energy, which it does by observing things such as distant type Ia supernovae and gravitational lensing. But while looking for such things, it also observes faint clusters of stars, and thus buried in its data is the evidence of these faint dwarf galaxies.

Finding these kinds of faint dwarf galaxies is important, because it could help solve a mystery of dark matter. Although dark matter is a successful theory in cosmology, with lots of evidence to support it, the model does have a few weak points. One of these concerns dwarf galaxies. Specifically, dark matter models predict that a galaxy like the Milky Way should have more dwarf galaxies orbiting them than we currently observe. One proposed solution is that there are many more dwarf galaxies out there, but they are dominated by dark matter and aren’t very bright. These newly discovered galaxies would seem to agree with this idea.

What’s interesting about these new dwarf galaxy candidates is that they seem be be clustered around the Small and Large Magellanic Clouds. This could mean that they could be satellite galaxies of the Magellanic galaxies. That’s still yet to be seen, but it is clear that our Milky Way has more dwarf galaxies hidden in the dark.

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I’m exhausted. I didn’t write a post yesterday because I was traveling back from Chile to Rochester. Normally I would have had a pre-written post, but in the past 10 days I’ve been on seven airline flights, traveled thousands of miles, stayed up far too late looking at stars, learning new things about astronomy in Chile and meeting new friends. My trip to Chile has been amazing, and it will take time for me to process it all and really start writing about it in a meaningful way. I had meant to write a general astronomy post today, but I can barely keep my eyes open. I’ll start writing regular posts … zzzzzzzz.

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The main site at ALMA is at an elevation of 16,400 feet. Roughly half the atmosphere is below you at that point, and oxygen levels are pretty low. It can have some minor adverse effects in the best conditions, and downright life-threatening effects in the worst. So you have to pass a basic physical on site, and if you don’t pass, you don’t get approved for the ALMA high site.

I didn’t pass.

So, as the pied piper led the children up the mountain, I was the boy left behind. While the rest of the ACEAP team is visiting the highest astronomy project in the world, I’m writing this, and the taste is bitter indeed.

There isn’t a clear trend for those who don’t pass. Overweight sedentary folks have passed while young, marathon-running vegetarians haven’t. It all depends on how you react to high altitudes. If the medics deem you too much of a risk, you don’t go, and there’s no arguing with them, as it should be. That “I’ll be fine” approach at high altitudes is how you get into trouble.

It’s tempting to sit and stew about it. Curl up a fist and start pounding sand. But that’s not how science works. On twitter right now there is buzz about the explosion of SpaceX’s Dragon this morning. I’m sure Elon Musk is having a bad day as well, so at least I’m in good company. I have a feeling, however, that Musk and his team aren’t going to pack it up and get out of the space business. Not everything happens as planned, in science and in life.

Find a crew. Find a job. Keep flying.

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As we’ve been traveling across Chile, we’ve seen billions of dollars worth of astronomical equipment. These are big projects, and in the case of ALMA, driven by a large multinational consortium. With all the money and effort put into creating these projects, you might think that the ability to use the facilities would be limited to an exclusive club of astronomers. Surprisingly, it’s not.

There are two things that come into play with big projects such as ALMA, Gemini and CTIO: observing time and data. In order to get observing time, you have to submit a proposal that goes through a review process. There are negotiated amounts dedicated to US, European and Chilean researchers, but there is also some observing time that is “open skies.” That means anyone can apply for that access time. And I mean anyone. You, me, and anyone else on the planet could submit a proposal for observing time. What’s more, you wouldn’t have to pay for that time. If your proposal is approved, you only pay for travel and lodging.

Now it’s true that proposals are extremely competitive, and you would need to have a great deal of skill to make a winning proposal. But you don’t need a degree, nor a university position. These telescopes truly are accessible to the public.

The same is true with the data gathered. In some cases there is a period where a team with observing time gets exclusive access to the data, but eventually it goes into the public domain. Anyone can access it for free. It’s not often in the most user friendly format, but it is available.

New telescopes such as the Large Synoptic Survey Telescope being built near Gemini South take that approach even more seriously, with plans shift away from dedicated observing time and towards immediate release of data to the public. Professional and amateur astronomers alike will have the same access to the data. LSST and other projects become a human endeavor rather.

After all, we all share the same sky, so why not share the same data?

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Yesterday we arrived at the Atacama region of Chile, and are staying in the small town of San Pedro. Atacama is perhaps the driest region in the world, and San Pedro is at an elevation of about 8,000 feet. That combination can be quite a punch. Fortunately we’ve been at a similar elevation the past couple of days at CTIO, so that isn’t too bad. The arid air, however, is a different story. Hydration is key at this point.

While Cerro Tololo had an almost overwhelming beauty to it, Atacama is a bit different. Magnificent desolation, to paraphrase Buzz Aldrin. But the arid and high conditions of the region are exactly why ALMA is here.

But that’s a story for tomorrow. For now it’s time to have a bit more water, and get some sleep.

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Astronomy requires dark and clear skies, and that often means you need to build telescopes in remote places such as Cerro Tololo, where we have been staying the past couple days. While it’s dark skies that brings us to Cerro Tololo, it as also a region of profound beauty. It is a land so wondrous that I feel inadequate to the task of describing it.

With the altitude, the days are often sunny and brilliant, and it’s important to limit direct exposure to the Sun. But twilight comes with a cool breeze and a fall of colors. This is a desert mountain range, so the mountains fade into the haze and are painted by the falling Sun. The sky is brilliant blue during the day, and at twilight darkens to a deep blue before yielding to the night.

Then the stars come out, tentative at first, then gathering to a sparkling sea. The Milky Way is high overhead in Winter, and is mingled with dark clouds. The stars are clear and close, and it’s hard to take it all in.

The should have sent a poet, but they sent me instead. And I’m very glad they did.

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