Turno #3 diversions

This turno got off to a delayed start, following an intense rain storm at the ALMA OSF (we hesitate to boast that this is the ``driest place in the world'' now).  Last week, the previous astronomers on shift were sent home early, and our trips were originally cancelled, then rescheduled a day later.  This meant that when I arrived at the OSF along with my supervisor, the first night we worked hard to quickly get the system going again and as many antennas as possible reinstated into the array.  Fortunately, the weather continued to improve throughout the week.  I hope this means the end of this year's "fuerte" (strong) altiplanic winter. 

After the rain, the mud dries into the most impressive formations I have ever seen (this is a parking lot that became covered in mud/dirt).  As the water evaporates, the sheets of mud crack and curl upwards around the edges.  A fun diversion can be to toss sheets of mud and watch them shatter into dust.  I have seen sheets several inches thick, and several feet long!  The desert is an amazing environment.

Each of the following nights, we had more and more antennas becoming available.  For various reasons, the array is always changing.  In this case, some antennas were being powered up after the storm, and others were being moved to a new configuration (unrelated to the storm).  To keep the telescope operating at very high precision, we need to know the exact location, focus, etc, of each antenna, and this process of measurements (called antenna integration) takes some serious time and attention.  Luckily, I was working with a good team and every night we made progress.


It wasn't always business as usual during this turno.  Here are a few notable distractions that kept things lively. 

Seen around ALMA -- The first is a video taken by the Project Scientist, just to show you that some creatures manage to survive in the harsh desert environment.  Creepy creatures like this one seem to do okay here.  Annoying flies and mice also call the ALMA site home. 

Visitors -- The ALMA Education and Public Outreach officer seems to stay busy coordinating visits to the ALMA site for journalists and photographers.  This weekend, we saw several new faces in the control room, including journalists from USA, France and Germany.  Of course, we had astronomers from, you guessed it, USA, France and Germany to talk with these visitors!  At first I was hesitant to be the USA voice for ALMA, since I too am only a visitor here.  At least I got to tour the North American antenna camp along with the journalists, and we saw one of the antennas being delivered by the transporter.  But, in the end, talking with the journalist made me even more excited about the project, especially the parts of this project that have never been done before, and it reminded me how fortunate I am to have this opportunity to work here. 

Also visiting ALMA was a photographer sent by ESO (European Southern Observatory) who is documenting telescopes for a book to celebrate the 50th anniversary of ESO this year.  He was photographing a group of us huddled around a computer that was controlling the antennas -- what we were doing could seem like a dull task, but actually it's exciting to be working with such a diverse group of people on a project that is always new.  One evening, we gathered a group outside for a photo with the sunset, and with Jupiter and Venus over our shoulders.  We were from Chile, USA, Japan, and Europe, personifying the agreement of the ALMA project. 

Getting outside -- We work a lot at ALMA, many hours spent in the control room staring at computers.  And while we accomplish a lot in that control room, I try to remember to also enjoy the incredible surroundings.  In all directions from the ALMA OSF are incredible views -- exploring around the ALMA site by day, or looking up at the sky at night. 

I went on two hikes with guys who work building antennas for ALMA, and who know the site very, very well.  We headed out walking north of the OSF, towards a giant cactus, and descended into a deep canyon that seemed to drop out of nowhere.  We followed the canyon as it wound through the nothing-ness, sometimes scrambling over boulders or hugging the walls of the rocky canyon to descend deeper.  To complicate matters, we had to avoid some pools of water after the recent rains, and the accompanying mud which always seemed to be some unknown consistency.  Fortunately, my new friends helped me along the way, I stayed dry and fairly mud-free, and I learned some more about the area, and about hiking in canyons (i.e. never go down somewhere that you may not be able to get back up).  I look forward to exploring this area even more.  Of course, next time I show up to our daily meeting after returning from a mid-day hike, I will make sure that I have cleaned the sunscreen and dirt off of my arms first…

Many years must have have shaped and rearranged the rocks in this canyon, like this boulder that we walked under.

It's not only the landscapes that are amazing here, but of course the sky is also impressive and infinite.  Last night one of the guys here set up a small optical telescope outside and we took a tour of the southern sky.  The highlights: a nebula in the Large Magellanic Cloud, a star cluster, the Sombrero Galaxy, the Orion Nebula and Saturn (okay, the last two are not uniquely southern, but they are especially awesome with such a clear sky).  We had spent several nights observing Saturn to calibrate the ALMA antennas, and to an ALMA antenna, Saturn is best seen as a spectrum with a little blip of light to signify a detection of the planet.  Exciting to us astronomers because it means the antenna is working.  But, not very aesthetically intriguing.  Last night, through the optical telescope, Saturn was more awesome than I have ever seen.  The rings were perfectly oriented, and we could even see the gap between the ring and the planet, several bands on the planet, plus several moons to the side.  It's good to remember that at its very essence, our research is really beautiful and somewhat mysterious, I think this keeps us motivated to continue exploring the universe. 

This photo of Saturn was taken with a camera pointing to the eyepiece of the 8-inch Celestron telescope. You have to see it to believe it.  Photo courtesy of an ALMA co-worker. 

Astrobites Post: An antenna array is a successful mix of apples and oranges

Here's my latest astrobites post, with some more details about the incredible ALMA antennas.  You'll learn about submillimeter interferometry, and why the 66 antennas at ALMA, built and operated by an international collaboration, make this the largest astronomy project in the world.

Did you know that the ALMA Array Operations Site (AOS) technical building is the second highest steel frame building in the world, at 5000 m?  If you can tell me what is the highest, I'll be really interested!

Real weather, simulated observations

We're nearing the end of the altiplanic winter here in the Atacama, which means (fingers crossed) we should get back to observing soon.  The other night we were very productive with observations, but last night was somewhat of a different story.  Snow at the array meant we were shut down for the night, limited to running the antennas in "simulation mode", which means we can test the software and the observing scripts, but the antennas only pretend to be observing (they're not supposed to actually move if there might be snow/ice on the surface).  So, the weather wreaked havoc on the observing plan, but it did bring some pretty dramatic (and admittedly incredible) scenes in the afternoon.  I tried to document it all.

(1) Sand storm -- In the time it took me to walk from my room to the control room, the sand storm blew by, probably about 10-20 km, which means it was moving about 60 km/hr (from my very rough estimates).  It fortunately didn't arrive all the way to the OSF (fortunately, because I hear the sand is impossible to dislodge from your ears, face, clothes, etc).  I wanted to capture the whole scene, because to the north was a thick cloud of sand, but to the south was still sunny and clear.  Above is the 360 panorama I patched together.  If you google something like "Atacama sand storm", you will see that this must be rather common after all, and produces plenty of intense scenes.

(2) Rain(bow) -- Every time it rains here, we head outside, just to feel the cool moisture on our skin.  Someone usually comments about how this should be the "driest place on earth".  Well, it did rain here, but it passed in less than 5 minutes.  Clouds in the direction of the antennas is not a good sign for the night, but at least the rain left behind a full rainbow.

(3) Cloudy (bad) sunset (good) -- Again, astronomers may regret to say that some cloud cover produces the most gorgeous sunsets.  Well, if we can't be observing, at least we can appreciate the beauty.  Here I was enjoying the sunset with one of the other astronomers on shift. 

(4) Snow vs. antenna -- An antenna makes the ~30 km journey from the OSF (3000 m elevation) to the AOS (5000 m elevation) very slowly and carefully, aboard the specially designed antenna transporter.  Any sign of weather, and the move is cancelled.  This afternoon, along with all of the other crazy weather that blew in, some snow arrived at the high site before the antenna, and the transporter was forced to turn around.  We (the astronomers and array operators) at least made lemonade from the lemon-y weather, and hung around to enjoy the show as the antenna was returned to its temporary home near the control building, where it will wait out the bad weather.  Check out more photos (uploaded on Picasa), and the video I took, but maybe it's better in fast-motion.  In case you're interested, the transporter has 28 wheels that can move independently, and can place the 100 ton antenna on its station with 1 mm of accuracy!!  The driver makes most of the journey in the cab, but for the final moves, the transporter is operated with a remote control (it seems sort of like a really exciting video game).   

... All of this exciting weather ultimately shut us down.  These were the most "real" things that happened, all within about 1 hour this evening, before we headed inside for the night of observing in "simulation" mode.  So, enjoy the photos and the dramatic stories now, and I hope that I won't have anything more to report of this nature in the future!!